Revert "Refcount all CFX_DIBSources (and subclasses) all the time."

This reverts commit 0004f29bf6ee3c6060a272c79f14993e92e053c7.

Reason for revert: Breaks build with skia_paths enabled (which will break the chrome roll).

../../third_party/pdfium/core/fxge/skia/fx_skia_device.cpp:1858:38: error: no member named 'get' in 'CFX_RetainPtr<CFX_DIBitmap>'
../../third_party/pdfium/core/fxge/skia/fx_skia_device.cpp:1861:42: error: no member named 'get' in 'CFX_RetainPtr<CFX_DIBitmap>'
../../third_party/pdfium/core/fxge/skia/fx_skia_device.cpp:2987:15: error: no viable overloaded '='
../../third_party/pdfium/core/fxge/skia/fx_skia_device.cpp:2991:18: error: no viable overloaded '='
../../third_party/pdfium/core/fxge/skia/fx_skia_device.cpp:2999:17: error: no viable overloaded '='
../../third_party/pdfium/core/fxge/skia/fx_skia_device.cpp:3001:43: error: no member named 'GetObject' in 'CFX_RetainPtr<CFX_DIBitmap>'



Original change's description:
> Refcount all CFX_DIBSources (and subclasses) all the time.
> 
> There are currently several ownership models for these objects,
> including ad-hoc logic for sharing and deletion, and the
> now-redundant CFX_DIBitmapRef externally-counted handle to the DIBs.
> 
> Replace them all with the internal refcount scheme.
> 
> Change-Id: I2db399dfc19219eda384f94cc989353b78ce2872
> Reviewed-on: https://pdfium-review.googlesource.com/3166
> Reviewed-by: dsinclair <dsinclair@chromium.org>
> Commit-Queue: dsinclair <dsinclair@chromium.org>
> 

TBR=thestig@chromium.org,tsepez@chromium.org,dsinclair@chromium.org,pdfium-reviews@googlegroups.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I678b1fbc5e666cf7a19372ebaff3270fb115ba5e
Reviewed-on: https://pdfium-review.googlesource.com/3243
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

7 files changed, 208 insertions, 191 deletions

diff --git a/core/fxge/dib/dib_int.h b/core/fxge/dib/dib_int.h
index a898a479a2..000003a9c6 100644
--- a/core/fxge/dib/dib_int.h
+++ b/core/fxge/dib/dib_int.h
@@ -71,7 +71,7 @@ class CStretchEngine {
                  int dest_width,
                  int dest_height,
                  const FX_RECT& clip_rect,
-                 const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                 const CFX_DIBSource* pSrcBitmap,
                  int flags);
   ~CStretchEngine();
 
@@ -91,7 +91,7 @@ class CStretchEngine {
   uint8_t* m_pDestScanline;
   uint8_t* m_pDestMaskScanline;
   FX_RECT m_SrcClip;
-  CFX_RetainPtr<CFX_DIBSource> m_pSource;
+  const CFX_DIBSource* m_pSource;
   uint32_t* m_pSrcPalette;
   int m_SrcWidth;
   int m_SrcHeight;
diff --git a/core/fxge/dib/fx_dib_composite.cpp b/core/fxge/dib/fx_dib_composite.cpp
index fb00cb855b..435a1ad9b6 100644
--- a/core/fxge/dib/fx_dib_composite.cpp
+++ b/core/fxge/dib/fx_dib_composite.cpp
@@ -3914,18 +3914,17 @@ void CFX_ScanlineCompositor::CompositeBitMaskLine(uint8_t* dest_scan,
   }
 }
 
-bool CFX_DIBitmap::CompositeBitmap(
-    int dest_left,
-    int dest_top,
-    int width,
-    int height,
-    const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
-    int src_left,
-    int src_top,
-    int blend_type,
-    const CFX_ClipRgn* pClipRgn,
-    bool bRgbByteOrder,
-    void* pIccTransform) {
+bool CFX_DIBitmap::CompositeBitmap(int dest_left,
+                                   int dest_top,
+                                   int width,
+                                   int height,
+                                   const CFX_DIBSource* pSrcBitmap,
+                                   int src_left,
+                                   int src_top,
+                                   int blend_type,
+                                   const CFX_ClipRgn* pClipRgn,
+                                   bool bRgbByteOrder,
+                                   void* pIccTransform) {
   if (!m_pBuffer) {
     return false;
   }
@@ -3939,11 +3938,11 @@ bool CFX_DIBitmap::CompositeBitmap(
   if (width == 0 || height == 0) {
     return true;
   }
-  CFX_RetainPtr<CFX_DIBitmap> pClipMask;
+  const CFX_DIBitmap* pClipMask = nullptr;
   FX_RECT clip_box;
   if (pClipRgn && pClipRgn->GetType() != CFX_ClipRgn::RectI) {
     ASSERT(pClipRgn->GetType() == CFX_ClipRgn::MaskF);
-    pClipMask = pClipRgn->GetMask();
+    pClipMask = pClipRgn->GetMask().GetObject();
     clip_box = pClipRgn->GetBox();
   }
   CFX_ScanlineCompositor compositor;
@@ -3955,7 +3954,7 @@ bool CFX_DIBitmap::CompositeBitmap(
   int dest_Bpp = m_bpp / 8;
   int src_Bpp = pSrcBitmap->GetBPP() / 8;
   bool bRgb = src_Bpp > 1 && !pSrcBitmap->IsCmykImage();
-  CFX_RetainPtr<CFX_DIBitmap> pSrcAlphaMask = pSrcBitmap->m_pAlphaMask;
+  CFX_DIBitmap* pSrcAlphaMask = pSrcBitmap->m_pAlphaMask;
   for (int row = 0; row < height; row++) {
     uint8_t* dest_scan =
         m_pBuffer + (dest_top + row) * m_Pitch + dest_left * dest_Bpp;
@@ -3991,7 +3990,7 @@ bool CFX_DIBitmap::CompositeMask(int dest_left,
                                  int dest_top,
                                  int width,
                                  int height,
-                                 const CFX_RetainPtr<CFX_DIBSource>& pMask,
+                                 const CFX_DIBSource* pMask,
                                  uint32_t color,
                                  int src_left,
                                  int src_top,
@@ -4018,11 +4017,11 @@ bool CFX_DIBitmap::CompositeMask(int dest_left,
   if (src_alpha == 0) {
     return true;
   }
-  CFX_RetainPtr<CFX_DIBitmap> pClipMask;
+  const CFX_DIBitmap* pClipMask = nullptr;
   FX_RECT clip_box;
   if (pClipRgn && pClipRgn->GetType() != CFX_ClipRgn::RectI) {
     ASSERT(pClipRgn->GetType() == CFX_ClipRgn::MaskF);
-    pClipMask = pClipRgn->GetMask();
+    pClipMask = pClipRgn->GetMask().GetObject();
     clip_box = pClipRgn->GetBox();
   }
   int src_bpp = pMask->GetBPP();
@@ -4283,7 +4282,7 @@ CFX_BitmapComposer::~CFX_BitmapComposer() {
   FX_Free(m_pAddClipScan);
 }
 
-void CFX_BitmapComposer::Compose(const CFX_RetainPtr<CFX_DIBitmap>& pDest,
+void CFX_BitmapComposer::Compose(CFX_DIBitmap* pDest,
                                  const CFX_ClipRgn* pClipRgn,
                                  int bitmap_alpha,
                                  uint32_t mask_color,
@@ -4304,8 +4303,9 @@ void CFX_BitmapComposer::Compose(const CFX_RetainPtr<CFX_DIBitmap>& pDest,
   m_BitmapAlpha = bitmap_alpha;
   m_MaskColor = mask_color;
   m_pClipMask = nullptr;
-  if (pClipRgn && pClipRgn->GetType() != CFX_ClipRgn::RectI)
-    m_pClipMask = pClipRgn->GetMask();
+  if (pClipRgn && pClipRgn->GetType() != CFX_ClipRgn::RectI) {
+    m_pClipMask = pClipRgn->GetMask().GetObject();
+  }
   m_bVertical = bVertical;
   m_bFlipX = bFlipX;
   m_bFlipY = bFlipY;
diff --git a/core/fxge/dib/fx_dib_convert.cpp b/core/fxge/dib/fx_dib_convert.cpp
index 624e1437e9..aad3f343e2 100644
--- a/core/fxge/dib/fx_dib_convert.cpp
+++ b/core/fxge/dib/fx_dib_convert.cpp
@@ -17,7 +17,7 @@ class CFX_Palette {
   CFX_Palette();
   ~CFX_Palette();
 
-  bool BuildPalette(const CFX_RetainPtr<CFX_DIBSource>& pBitmap);
+  bool BuildPalette(const CFX_DIBSource* pBitmap);
   uint32_t* GetPalette() const { return m_pPalette; }
   uint32_t* GetColorLut() const { return m_cLut; }
   uint32_t* GetAmountLut() const { return m_aLut; }
@@ -101,7 +101,7 @@ CFX_Palette::~CFX_Palette() {
   m_lut = 0;
 }
 
-bool CFX_Palette::BuildPalette(const CFX_RetainPtr<CFX_DIBSource>& pBitmap) {
+bool CFX_Palette::BuildPalette(const CFX_DIBSource* pBitmap) {
   if (!pBitmap) {
     return false;
   }
@@ -145,7 +145,7 @@ bool ConvertBuffer_1bppMask2Gray(uint8_t* dest_buf,
                                  int dest_pitch,
                                  int width,
                                  int height,
-                                 const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                                 const CFX_DIBSource* pSrcBitmap,
                                  int src_left,
                                  int src_top) {
   uint8_t set_gray, reset_gray;
@@ -169,7 +169,7 @@ bool ConvertBuffer_8bppMask2Gray(uint8_t* dest_buf,
                                  int dest_pitch,
                                  int width,
                                  int height,
-                                 const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                                 const CFX_DIBSource* pSrcBitmap,
                                  int src_left,
                                  int src_top) {
   for (int row = 0; row < height; row++) {
@@ -184,7 +184,7 @@ bool ConvertBuffer_1bppPlt2Gray(uint8_t* dest_buf,
                                 int dest_pitch,
                                 int width,
                                 int height,
-                                const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                                const CFX_DIBSource* pSrcBitmap,
                                 int src_left,
                                 int src_top) {
   uint32_t* src_plt = pSrcBitmap->GetPalette();
@@ -231,7 +231,7 @@ bool ConvertBuffer_8bppPlt2Gray(uint8_t* dest_buf,
                                 int dest_pitch,
                                 int width,
                                 int height,
-                                const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                                const CFX_DIBSource* pSrcBitmap,
                                 int src_left,
                                 int src_top) {
   uint32_t* src_plt = pSrcBitmap->GetPalette();
@@ -263,14 +263,13 @@ bool ConvertBuffer_8bppPlt2Gray(uint8_t* dest_buf,
   return true;
 }
 
-bool ConvertBuffer_RgbOrCmyk2Gray(
-    uint8_t* dest_buf,
-    int dest_pitch,
-    int width,
-    int height,
-    const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
-    int src_left,
-    int src_top) {
+bool ConvertBuffer_RgbOrCmyk2Gray(uint8_t* dest_buf,
+                                  int dest_pitch,
+                                  int width,
+                                  int height,
+                                  const CFX_DIBSource* pSrcBitmap,
+                                  int src_left,
+                                  int src_top) {
   int Bpp = pSrcBitmap->GetBPP() / 8;
   if (pSrcBitmap->IsCmykImage()) {
     for (int row = 0; row < height; row++) {
@@ -305,7 +304,7 @@ void ConvertBuffer_IndexCopy(uint8_t* dest_buf,
                              int dest_pitch,
                              int width,
                              int height,
-                             const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                             const CFX_DIBSource* pSrcBitmap,
                              int src_left,
                              int src_top) {
   if (pSrcBitmap->GetBPP() == 1) {
@@ -334,7 +333,7 @@ bool ConvertBuffer_Plt2PltRgb8(uint8_t* dest_buf,
                                int dest_pitch,
                                int width,
                                int height,
-                               const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                               const CFX_DIBSource* pSrcBitmap,
                                int src_left,
                                int src_top,
                                uint32_t* dst_plt) {
@@ -362,7 +361,7 @@ bool ConvertBuffer_Rgb2PltRgb8(uint8_t* dest_buf,
                                int dest_pitch,
                                int width,
                                int height,
-                               const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                               const CFX_DIBSource* pSrcBitmap,
                                int src_left,
                                int src_top,
                                uint32_t* dst_plt) {
@@ -425,7 +424,7 @@ bool ConvertBuffer_1bppMask2Rgb(FXDIB_Format dst_format,
                                 int dest_pitch,
                                 int width,
                                 int height,
-                                const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                                const CFX_DIBSource* pSrcBitmap,
                                 int src_left,
                                 int src_top) {
   int comps = (dst_format & 0xff) / 8;
@@ -456,7 +455,7 @@ bool ConvertBuffer_8bppMask2Rgb(FXDIB_Format dst_format,
                                 int dest_pitch,
                                 int width,
                                 int height,
-                                const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                                const CFX_DIBSource* pSrcBitmap,
                                 int src_left,
                                 int src_top) {
   int comps = (dst_format & 0xff) / 8;
@@ -480,7 +479,7 @@ bool ConvertBuffer_1bppPlt2Rgb(FXDIB_Format dst_format,
                                int dest_pitch,
                                int width,
                                int height,
-                               const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                               const CFX_DIBSource* pSrcBitmap,
                                int src_left,
                                int src_top) {
   int comps = (dst_format & 0xff) / 8;
@@ -532,7 +531,7 @@ bool ConvertBuffer_8bppPlt2Rgb(FXDIB_Format dst_format,
                                int dest_pitch,
                                int width,
                                int height,
-                               const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                               const CFX_DIBSource* pSrcBitmap,
                                int src_left,
                                int src_top) {
   int comps = (dst_format & 0xff) / 8;
@@ -573,14 +572,13 @@ bool ConvertBuffer_8bppPlt2Rgb(FXDIB_Format dst_format,
   return true;
 }
 
-bool ConvertBuffer_24bppRgb2Rgb24(
-    uint8_t* dest_buf,
-    int dest_pitch,
-    int width,
-    int height,
-    const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
-    int src_left,
-    int src_top) {
+bool ConvertBuffer_24bppRgb2Rgb24(uint8_t* dest_buf,
+                                  int dest_pitch,
+                                  int width,
+                                  int height,
+                                  const CFX_DIBSource* pSrcBitmap,
+                                  int src_left,
+                                  int src_top) {
   for (int row = 0; row < height; row++) {
     uint8_t* dest_scan = dest_buf + row * dest_pitch;
     const uint8_t* src_scan =
@@ -590,14 +588,13 @@ bool ConvertBuffer_24bppRgb2Rgb24(
   return true;
 }
 
-bool ConvertBuffer_32bppRgb2Rgb24(
-    uint8_t* dest_buf,
-    int dest_pitch,
-    int width,
-    int height,
-    const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
-    int src_left,
-    int src_top) {
+bool ConvertBuffer_32bppRgb2Rgb24(uint8_t* dest_buf,
+                                  int dest_pitch,
+                                  int width,
+                                  int height,
+                                  const CFX_DIBSource* pSrcBitmap,
+                                  int src_left,
+                                  int src_top) {
   for (int row = 0; row < height; row++) {
     uint8_t* dest_scan = dest_buf + row * dest_pitch;
     const uint8_t* src_scan =
@@ -616,7 +613,7 @@ bool ConvertBuffer_Rgb2Rgb32(uint8_t* dest_buf,
                              int dest_pitch,
                              int width,
                              int height,
-                             const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                             const CFX_DIBSource* pSrcBitmap,
                              int src_left,
                              int src_top) {
   int comps = pSrcBitmap->GetBPP() / 8;
@@ -635,14 +632,13 @@ bool ConvertBuffer_Rgb2Rgb32(uint8_t* dest_buf,
   return true;
 }
 
-bool ConvertBuffer_32bppCmyk2Rgb32(
-    uint8_t* dest_buf,
-    int dest_pitch,
-    int width,
-    int height,
-    const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
-    int src_left,
-    int src_top) {
+bool ConvertBuffer_32bppCmyk2Rgb32(uint8_t* dest_buf,
+                                   int dest_pitch,
+                                   int width,
+                                   int height,
+                                   const CFX_DIBSource* pSrcBitmap,
+                                   int src_left,
+                                   int src_top) {
   for (int row = 0; row < height; row++) {
     uint8_t* dest_scan = dest_buf + row * dest_pitch;
     const uint8_t* src_scan =
@@ -662,7 +658,7 @@ bool ConvertBuffer(FXDIB_Format dest_format,
                    int dest_pitch,
                    int width,
                    int height,
-                   const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                   const CFX_DIBSource* pSrcBitmap,
                    int src_left,
                    int src_top,
                    std::unique_ptr<uint32_t, FxFreeDeleter>* p_pal) {
@@ -787,16 +783,16 @@ bool ConvertBuffer(FXDIB_Format dest_format,
   }
 }
 
-CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::CloneConvert(
-    FXDIB_Format dest_format) {
+std::unique_ptr<CFX_DIBitmap> CFX_DIBSource::CloneConvert(
+    FXDIB_Format dest_format) const {
   if (dest_format == GetFormat())
     return Clone(nullptr);
 
-  auto pClone = pdfium::MakeRetain<CFX_DIBitmap>();
+  std::unique_ptr<CFX_DIBitmap> pClone = pdfium::MakeUnique<CFX_DIBitmap>();
   if (!pClone->Create(m_Width, m_Height, dest_format))
     return nullptr;
 
-  CFX_RetainPtr<CFX_DIBitmap> pSrcAlpha;
+  CFX_MaybeOwned<CFX_DIBitmap> pSrcAlpha;
   if (HasAlpha()) {
     if (GetFormat() == FXDIB_Argb)
       pSrcAlpha = CloneAlphaMask();
@@ -809,19 +805,19 @@ CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::CloneConvert(
   bool ret = true;
   if (dest_format & 0x0200) {
     if (dest_format == FXDIB_Argb) {
-      ret = pSrcAlpha ? pClone->LoadChannel(FXDIB_Alpha, pSrcAlpha, FXDIB_Alpha)
-                      : pClone->LoadChannel(FXDIB_Alpha, 0xff);
+      ret = pSrcAlpha
+                ? pClone->LoadChannel(FXDIB_Alpha, pSrcAlpha.Get(), FXDIB_Alpha)
+                : pClone->LoadChannel(FXDIB_Alpha, 0xff);
     } else {
-      ret = pClone->SetAlphaMask(pSrcAlpha);
+      ret = pClone->SetAlphaMask(pSrcAlpha.Get());
     }
   }
   if (!ret)
     return nullptr;
 
-  CFX_RetainPtr<CFX_DIBSource> holder(this);
   std::unique_ptr<uint32_t, FxFreeDeleter> pal_8bpp;
   if (!ConvertBuffer(dest_format, pClone->GetBuffer(), pClone->GetPitch(),
-                     m_Width, m_Height, holder, 0, 0, &pal_8bpp)) {
+                     m_Width, m_Height, this, 0, 0, &pal_8bpp)) {
     return nullptr;
   }
   if (pal_8bpp)
@@ -857,7 +853,7 @@ bool CFX_DIBitmap::ConvertFormat(FXDIB_Format dest_format) {
   if (!dest_buf) {
     return false;
   }
-  CFX_RetainPtr<CFX_DIBitmap> pAlphaMask;
+  CFX_DIBitmap* pAlphaMask = nullptr;
   if (dest_format == FXDIB_Argb) {
     FXSYS_memset(dest_buf, 0xff, dest_pitch * m_Height + 4);
     if (m_pAlphaMask) {
@@ -872,7 +868,7 @@ bool CFX_DIBitmap::ConvertFormat(FXDIB_Format dest_format) {
     }
   } else if (dest_format & 0x0200) {
     if (src_format == FXDIB_Argb) {
-      pAlphaMask = CloneAlphaMask();
+      pAlphaMask = CloneAlphaMask().release();
       if (!pAlphaMask) {
         FX_Free(dest_buf);
         return false;
@@ -883,21 +879,25 @@ bool CFX_DIBitmap::ConvertFormat(FXDIB_Format dest_format) {
           FX_Free(dest_buf);
           return false;
         }
-        pAlphaMask = std::move(m_pAlphaMask);
+        pAlphaMask = m_pAlphaMask;
+        m_pAlphaMask = nullptr;
       } else {
         pAlphaMask = m_pAlphaMask;
       }
     }
   }
   bool ret = false;
-  CFX_RetainPtr<CFX_DIBSource> holder(this);
   std::unique_ptr<uint32_t, FxFreeDeleter> pal_8bpp;
   ret = ConvertBuffer(dest_format, dest_buf, dest_pitch, m_Width, m_Height,
-                      holder, 0, 0, &pal_8bpp);
+                      this, 0, 0, &pal_8bpp);
   if (!ret) {
+    if (pAlphaMask != m_pAlphaMask)
+      delete pAlphaMask;
     FX_Free(dest_buf);
     return false;
   }
+  if (m_pAlphaMask && pAlphaMask != m_pAlphaMask)
+    delete m_pAlphaMask;
   m_pAlphaMask = pAlphaMask;
   m_pPalette = std::move(pal_8bpp);
   if (!m_bExtBuf)
diff --git a/core/fxge/dib/fx_dib_engine.cpp b/core/fxge/dib/fx_dib_engine.cpp
index 7aa710b795..5975a5e975 100644
--- a/core/fxge/dib/fx_dib_engine.cpp
+++ b/core/fxge/dib/fx_dib_engine.cpp
@@ -265,7 +265,7 @@ CStretchEngine::CStretchEngine(IFX_ScanlineComposer* pDestBitmap,
                                int dest_width,
                                int dest_height,
                                const FX_RECT& clip_rect,
-                               const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                               const CFX_DIBSource* pSrcBitmap,
                                int flags) {
   m_State = 0;
   m_DestFormat = dest_format;
@@ -852,13 +852,12 @@ void CStretchEngine::StretchVert() {
   }
 }
 
-CFX_ImageStretcher::CFX_ImageStretcher(
-    IFX_ScanlineComposer* pDest,
-    const CFX_RetainPtr<CFX_DIBSource>& pSource,
-    int dest_width,
-    int dest_height,
-    const FX_RECT& bitmap_rect,
-    uint32_t flags)
+CFX_ImageStretcher::CFX_ImageStretcher(IFX_ScanlineComposer* pDest,
+                                       const CFX_DIBSource* pSource,
+                                       int dest_width,
+                                       int dest_height,
+                                       const FX_RECT& bitmap_rect,
+                                       uint32_t flags)
     : m_pDest(pDest),
       m_pSource(pSource),
       m_Flags(flags),
diff --git a/core/fxge/dib/fx_dib_engine_unittest.cpp b/core/fxge/dib/fx_dib_engine_unittest.cpp
index 86df82442f..705d761ca8 100644
--- a/core/fxge/dib/fx_dib_engine_unittest.cpp
+++ b/core/fxge/dib/fx_dib_engine_unittest.cpp
@@ -23,9 +23,9 @@ TEST(CStretchEngine, OverflowInCtor) {
   dict_obj->SetNewFor<CPDF_Number>("Height", 12500);
   std::unique_ptr<CPDF_Stream> stream =
       pdfium::MakeUnique<CPDF_Stream>(nullptr, 0, std::move(dict_obj));
-  auto dib_source = pdfium::MakeRetain<CPDF_DIBSource>();
-  dib_source->Load(nullptr, stream.get());
-  CStretchEngine engine(nullptr, FXDIB_8bppRgb, 500, 500, clip_rect, dib_source,
-                        0);
+  CPDF_DIBSource dib_source;
+  dib_source.Load(nullptr, stream.get());
+  CStretchEngine engine(nullptr, FXDIB_8bppRgb, 500, 500, clip_rect,
+                        &dib_source, 0);
   EXPECT_EQ(FXDIB_INTERPOL, engine.m_Flags);
 }
diff --git a/core/fxge/dib/fx_dib_main.cpp b/core/fxge/dib/fx_dib_main.cpp
index 8a97d342b5..96cae9d4e7 100644
--- a/core/fxge/dib/fx_dib_main.cpp
+++ b/core/fxge/dib/fx_dib_main.cpp
@@ -44,9 +44,16 @@ uint32_t ArgbEncode(int a, FX_COLORREF rgb) {
 }
 
 CFX_DIBSource::CFX_DIBSource()
-    : m_Width(0), m_Height(0), m_bpp(0), m_AlphaFlag(0), m_Pitch(0) {}
-
-CFX_DIBSource::~CFX_DIBSource() {}
+    : m_pAlphaMask(nullptr),
+      m_Width(0),
+      m_Height(0),
+      m_bpp(0),
+      m_AlphaFlag(0),
+      m_Pitch(0) {}
+
+CFX_DIBSource::~CFX_DIBSource() {
+  delete m_pAlphaMask;
+}
 
 uint8_t* CFX_DIBSource::GetBuffer() const {
   return nullptr;
@@ -120,7 +127,7 @@ bool CFX_DIBitmap::Create(int width,
   return true;
 }
 
-bool CFX_DIBitmap::Copy(const CFX_RetainPtr<CFX_DIBSource>& pSrc) {
+bool CFX_DIBitmap::Copy(const CFX_DIBSource* pSrc) {
   if (m_pBuffer)
     return false;
 
@@ -150,10 +157,11 @@ const uint8_t* CFX_DIBitmap::GetScanline(int line) const {
   return m_pBuffer ? m_pBuffer + line * m_Pitch : nullptr;
 }
 
-void CFX_DIBitmap::TakeOver(CFX_RetainPtr<CFX_DIBitmap>&& pSrcBitmap) {
+void CFX_DIBitmap::TakeOver(CFX_DIBitmap* pSrcBitmap) {
   if (!m_bExtBuf)
     FX_Free(m_pBuffer);
 
+  delete m_pAlphaMask;
   m_pBuffer = pSrcBitmap->m_pBuffer;
   m_pPalette = std::move(pSrcBitmap->m_pPalette);
   m_pAlphaMask = pSrcBitmap->m_pAlphaMask;
@@ -167,14 +175,14 @@ void CFX_DIBitmap::TakeOver(CFX_RetainPtr<CFX_DIBitmap>&& pSrcBitmap) {
   m_Pitch = pSrcBitmap->m_Pitch;
 }
 
-CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::Clone(const FX_RECT* pClip) const {
+std::unique_ptr<CFX_DIBitmap> CFX_DIBSource::Clone(const FX_RECT* pClip) const {
   FX_RECT rect(0, 0, m_Width, m_Height);
   if (pClip) {
     rect.Intersect(*pClip);
     if (rect.IsEmpty())
       return nullptr;
   }
-  auto pNewBitmap = pdfium::MakeRetain<CFX_DIBitmap>();
+  auto pNewBitmap = pdfium::MakeUnique<CFX_DIBitmap>();
   if (!pNewBitmap->Create(rect.Width(), rect.Height(), GetFormat()))
     return nullptr;
 
@@ -232,11 +240,12 @@ void CFX_DIBSource::BuildPalette() {
 }
 
 bool CFX_DIBSource::BuildAlphaMask() {
-  if (m_pAlphaMask)
+  if (m_pAlphaMask) {
     return true;
-
-  m_pAlphaMask = pdfium::MakeRetain<CFX_DIBitmap>();
+  }
+  m_pAlphaMask = new CFX_DIBitmap;
   if (!m_pAlphaMask->Create(m_Width, m_Height, FXDIB_8bppMask)) {
+    delete m_pAlphaMask;
     m_pAlphaMask = nullptr;
     return false;
   }
@@ -392,14 +401,13 @@ void CFX_DIBSource::GetOverlapRect(int& dest_left,
   height = dest_rect.bottom - dest_rect.top;
 }
 
-bool CFX_DIBitmap::TransferBitmap(
-    int dest_left,
-    int dest_top,
-    int width,
-    int height,
-    const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
-    int src_left,
-    int src_top) {
+bool CFX_DIBitmap::TransferBitmap(int dest_left,
+                                  int dest_top,
+                                  int width,
+                                  int height,
+                                  const CFX_DIBSource* pSrcBitmap,
+                                  int src_left,
+                                  int src_top) {
   if (!m_pBuffer)
     return false;
 
@@ -458,7 +466,7 @@ bool CFX_DIBitmap::TransferMask(int dest_left,
                                 int dest_top,
                                 int width,
                                 int height,
-                                const CFX_RetainPtr<CFX_DIBSource>& pMask,
+                                const CFX_DIBSource* pMask,
                                 uint32_t color,
                                 int src_left,
                                 int src_top,
@@ -597,7 +605,7 @@ void CFX_DIBSource::GetPalette(uint32_t* pal, int alpha) const {
   }
 }
 
-CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::CloneAlphaMask(
+std::unique_ptr<CFX_DIBitmap> CFX_DIBSource::CloneAlphaMask(
     const FX_RECT* pClip) const {
   ASSERT(GetFormat() == FXDIB_Argb);
   FX_RECT rect(0, 0, m_Width, m_Height);
@@ -606,7 +614,7 @@ CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::CloneAlphaMask(
     if (rect.IsEmpty())
       return nullptr;
   }
-  auto pMask = pdfium::MakeRetain<CFX_DIBitmap>();
+  auto pMask = pdfium::MakeUnique<CFX_DIBitmap>();
   if (!pMask->Create(rect.Width(), rect.Height(), FXDIB_8bppMask))
     return nullptr;
 
@@ -622,7 +630,7 @@ CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::CloneAlphaMask(
   return pMask;
 }
 
-bool CFX_DIBSource::SetAlphaMask(const CFX_RetainPtr<CFX_DIBSource>& pAlphaMask,
+bool CFX_DIBSource::SetAlphaMask(const CFX_DIBSource* pAlphaMask,
                                  const FX_RECT* pClip) {
   if (!HasAlpha() || GetFormat() == FXDIB_Argb)
     return false;
@@ -652,12 +660,12 @@ bool CFX_DIBSource::SetAlphaMask(const CFX_RetainPtr<CFX_DIBSource>& pAlphaMask,
 
 const int g_ChannelOffset[] = {0, 2, 1, 0, 0, 1, 2, 3, 3};
 bool CFX_DIBitmap::LoadChannel(FXDIB_Channel destChannel,
-                               const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap,
+                               CFX_DIBSource* pSrcBitmap,
                                FXDIB_Channel srcChannel) {
   if (!m_pBuffer)
     return false;
 
-  CFX_RetainPtr<CFX_DIBSource> pSrcClone = pSrcBitmap;
+  CFX_MaybeOwned<CFX_DIBSource> pSrcClone(pSrcBitmap);
   int srcOffset;
   if (srcChannel == FXDIB_Alpha) {
     if (!pSrcBitmap->HasAlpha() && !pSrcBitmap->IsAlphaMask())
@@ -717,7 +725,7 @@ bool CFX_DIBitmap::LoadChannel(FXDIB_Channel destChannel,
     destOffset = g_ChannelOffset[destChannel];
   }
   if (srcChannel == FXDIB_Alpha && pSrcClone->m_pAlphaMask) {
-    CFX_RetainPtr<CFX_DIBSource> pAlphaMask = pSrcClone->m_pAlphaMask;
+    CFX_MaybeOwned<CFX_DIBSource> pAlphaMask(pSrcClone->m_pAlphaMask);
     if (pSrcClone->GetWidth() != m_Width ||
         pSrcClone->GetHeight() != m_Height) {
       if (pAlphaMask) {
@@ -730,14 +738,14 @@ bool CFX_DIBitmap::LoadChannel(FXDIB_Channel destChannel,
     srcOffset = 0;
   } else if (pSrcClone->GetWidth() != m_Width ||
              pSrcClone->GetHeight() != m_Height) {
-    CFX_RetainPtr<CFX_DIBitmap> pSrcMatched =
+    std::unique_ptr<CFX_DIBitmap> pSrcMatched =
         pSrcClone->StretchTo(m_Width, m_Height);
     if (!pSrcMatched)
       return false;
 
     pSrcClone = std::move(pSrcMatched);
   }
-  CFX_RetainPtr<CFX_DIBitmap> pDst(this);
+  CFX_DIBitmap* pDst = this;
   if (destChannel == FXDIB_Alpha && m_pAlphaMask) {
     pDst = m_pAlphaMask;
     destOffset = 0;
@@ -815,8 +823,7 @@ bool CFX_DIBitmap::LoadChannel(FXDIB_Channel destChannel, int value) {
   return true;
 }
 
-bool CFX_DIBitmap::MultiplyAlpha(
-    const CFX_RetainPtr<CFX_DIBSource>& pSrcBitmap) {
+bool CFX_DIBitmap::MultiplyAlpha(CFX_DIBSource* pSrcBitmap) {
   if (!m_pBuffer)
     return false;
 
@@ -827,7 +834,8 @@ bool CFX_DIBitmap::MultiplyAlpha(
   if (!IsAlphaMask() && !HasAlpha())
     return LoadChannel(FXDIB_Alpha, pSrcBitmap, FXDIB_Alpha);
 
-  CFX_RetainPtr<CFX_DIBitmap> pSrcClone = pSrcBitmap.As<CFX_DIBitmap>();
+  CFX_MaybeOwned<CFX_DIBitmap> pSrcClone(
+      static_cast<CFX_DIBitmap*>(pSrcBitmap));
   if (pSrcBitmap->GetWidth() != m_Width ||
       pSrcBitmap->GetHeight() != m_Height) {
     pSrcClone = pSrcBitmap->StretchTo(m_Width, m_Height);
@@ -867,7 +875,7 @@ bool CFX_DIBitmap::MultiplyAlpha(
         }
       }
     } else {
-      m_pAlphaMask->MultiplyAlpha(pSrcClone);
+      m_pAlphaMask->MultiplyAlpha(pSrcClone.Get());
     }
   }
   return true;
@@ -879,9 +887,9 @@ bool CFX_DIBitmap::GetGrayData(void* pIccTransform) {
   }
   switch (GetFormat()) {
     case FXDIB_1bppRgb: {
-      if (!m_pPalette)
+      if (!m_pPalette) {
         return false;
-
+      }
       uint8_t gray[2];
       for (int i = 0; i < 2; i++) {
         int r = static_cast<uint8_t>(m_pPalette.get()[i] >> 16);
@@ -889,10 +897,11 @@ bool CFX_DIBitmap::GetGrayData(void* pIccTransform) {
         int b = static_cast<uint8_t>(m_pPalette.get()[i]);
         gray[i] = static_cast<uint8_t>(FXRGB2GRAY(r, g, b));
       }
-      auto pMask = pdfium::MakeRetain<CFX_DIBitmap>();
-      if (!pMask->Create(m_Width, m_Height, FXDIB_8bppMask))
+      CFX_DIBitmap* pMask = new CFX_DIBitmap;
+      if (!pMask->Create(m_Width, m_Height, FXDIB_8bppMask)) {
+        delete pMask;
         return false;
-
+      }
       FXSYS_memset(pMask->GetBuffer(), gray[0], pMask->GetPitch() * m_Height);
       for (int row = 0; row < m_Height; row++) {
         uint8_t* src_pos = m_pBuffer + row * m_Pitch;
@@ -904,13 +913,14 @@ bool CFX_DIBitmap::GetGrayData(void* pIccTransform) {
           dest_pos++;
         }
       }
-      TakeOver(std::move(pMask));
+      TakeOver(pMask);
+      delete pMask;
       break;
     }
     case FXDIB_8bppRgb: {
-      if (!m_pPalette)
+      if (!m_pPalette) {
         return false;
-
+      }
       uint8_t gray[256];
       for (int i = 0; i < 256; i++) {
         int r = static_cast<uint8_t>(m_pPalette.get()[i] >> 16);
@@ -918,10 +928,11 @@ bool CFX_DIBitmap::GetGrayData(void* pIccTransform) {
         int b = static_cast<uint8_t>(m_pPalette.get()[i]);
         gray[i] = static_cast<uint8_t>(FXRGB2GRAY(r, g, b));
       }
-      auto pMask = pdfium::MakeRetain<CFX_DIBitmap>();
-      if (!pMask->Create(m_Width, m_Height, FXDIB_8bppMask))
+      CFX_DIBitmap* pMask = new CFX_DIBitmap;
+      if (!pMask->Create(m_Width, m_Height, FXDIB_8bppMask)) {
+        delete pMask;
         return false;
-
+      }
       for (int row = 0; row < m_Height; row++) {
         uint8_t* dest_pos = pMask->GetBuffer() + row * pMask->GetPitch();
         uint8_t* src_pos = m_pBuffer + row * m_Pitch;
@@ -929,14 +940,16 @@ bool CFX_DIBitmap::GetGrayData(void* pIccTransform) {
           *dest_pos++ = gray[*src_pos++];
         }
       }
-      TakeOver(std::move(pMask));
+      TakeOver(pMask);
+      delete pMask;
       break;
     }
     case FXDIB_Rgb: {
-      auto pMask = pdfium::MakeRetain<CFX_DIBitmap>();
-      if (!pMask->Create(m_Width, m_Height, FXDIB_8bppMask))
+      CFX_DIBitmap* pMask = new CFX_DIBitmap;
+      if (!pMask->Create(m_Width, m_Height, FXDIB_8bppMask)) {
+        delete pMask;
         return false;
-
+      }
       for (int row = 0; row < m_Height; row++) {
         uint8_t* src_pos = m_pBuffer + row * m_Pitch;
         uint8_t* dest_pos = pMask->GetBuffer() + row * pMask->GetPitch();
@@ -945,14 +958,16 @@ bool CFX_DIBitmap::GetGrayData(void* pIccTransform) {
           src_pos += 3;
         }
       }
-      TakeOver(std::move(pMask));
+      TakeOver(pMask);
+      delete pMask;
       break;
     }
     case FXDIB_Rgb32: {
-      auto pMask = pdfium::MakeRetain<CFX_DIBitmap>();
-      if (!pMask->Create(m_Width, m_Height, FXDIB_8bppMask))
+      CFX_DIBitmap* pMask = new CFX_DIBitmap;
+      if (!pMask->Create(m_Width, m_Height, FXDIB_8bppMask)) {
+        delete pMask;
         return false;
-
+      }
       for (int row = 0; row < m_Height; row++) {
         uint8_t* src_pos = m_pBuffer + row * m_Pitch;
         uint8_t* dest_pos = pMask->GetBuffer() + row * pMask->GetPitch();
@@ -961,7 +976,8 @@ bool CFX_DIBitmap::GetGrayData(void* pIccTransform) {
           src_pos += 4;
         }
       }
-      TakeOver(std::move(pMask));
+      TakeOver(pMask);
+      delete pMask;
       break;
     }
     default:
@@ -1326,9 +1342,9 @@ bool CFX_DIBitmap::ConvertColorScale(uint32_t forecolor, uint32_t backcolor) {
   return true;
 }
 
-CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::FlipImage(bool bXFlip,
-                                                     bool bYFlip) const {
-  auto pFlipped = pdfium::MakeRetain<CFX_DIBitmap>();
+std::unique_ptr<CFX_DIBitmap> CFX_DIBSource::FlipImage(bool bXFlip,
+                                                       bool bYFlip) const {
+  auto pFlipped = pdfium::MakeUnique<CFX_DIBitmap>();
   if (!pFlipped->Create(m_Width, m_Height, GetFormat()))
     return nullptr;
 
@@ -1398,12 +1414,12 @@ CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::FlipImage(bool bXFlip,
   return pFlipped;
 }
 
-CFX_DIBExtractor::CFX_DIBExtractor(const CFX_RetainPtr<CFX_DIBSource>& pSrc) {
+CFX_DIBExtractor::CFX_DIBExtractor(const CFX_DIBSource* pSrc) {
   if (pSrc->GetBuffer()) {
-    m_pBitmap = pdfium::MakeRetain<CFX_DIBitmap>();
+    m_pBitmap = pdfium::MakeUnique<CFX_DIBitmap>();
     if (!m_pBitmap->Create(pSrc->GetWidth(), pSrc->GetHeight(),
                            pSrc->GetFormat(), pSrc->GetBuffer())) {
-      m_pBitmap.Reset();
+      m_pBitmap.reset();
       return;
     }
     m_pBitmap->SetPalette(pSrc->GetPalette());
@@ -1415,12 +1431,17 @@ CFX_DIBExtractor::CFX_DIBExtractor(const CFX_RetainPtr<CFX_DIBSource>& pSrc) {
 
 CFX_DIBExtractor::~CFX_DIBExtractor() {}
 
-CFX_FilteredDIB::CFX_FilteredDIB() {}
+CFX_FilteredDIB::CFX_FilteredDIB() : m_pSrc(nullptr) {}
 
-CFX_FilteredDIB::~CFX_FilteredDIB() {}
+CFX_FilteredDIB::~CFX_FilteredDIB() {
+  if (m_bAutoDropSrc) {
+    delete m_pSrc;
+  }
+}
 
-void CFX_FilteredDIB::LoadSrc(const CFX_RetainPtr<CFX_DIBSource>& pSrc) {
+void CFX_FilteredDIB::LoadSrc(const CFX_DIBSource* pSrc, bool bAutoDropSrc) {
   m_pSrc = pSrc;
+  m_bAutoDropSrc = bAutoDropSrc;
   m_Width = pSrc->GetWidth();
   m_Height = pSrc->GetHeight();
   FXDIB_Format format = GetDestFormat();
@@ -1457,9 +1478,9 @@ CFX_ImageRenderer::CFX_ImageRenderer() {
 
 CFX_ImageRenderer::~CFX_ImageRenderer() {}
 
-bool CFX_ImageRenderer::Start(const CFX_RetainPtr<CFX_DIBitmap>& pDevice,
+bool CFX_ImageRenderer::Start(CFX_DIBitmap* pDevice,
                               const CFX_ClipRgn* pClipRgn,
-                              const CFX_RetainPtr<CFX_DIBSource>& pSource,
+                              const CFX_DIBSource* pSource,
                               int bitmap_alpha,
                               uint32_t mask_color,
                               const CFX_Matrix* pMatrix,
@@ -1548,7 +1569,7 @@ bool CFX_ImageRenderer::Continue(IFX_Pause* pPause) {
     if (m_pTransformer->Continue(pPause))
       return true;
 
-    CFX_RetainPtr<CFX_DIBitmap> pBitmap = m_pTransformer->DetachBitmap();
+    std::unique_ptr<CFX_DIBitmap> pBitmap(m_pTransformer->DetachBitmap());
     if (!pBitmap || !pBitmap->GetBuffer())
       return false;
 
@@ -1564,16 +1585,16 @@ bool CFX_ImageRenderer::Continue(IFX_Pause* pPause) {
       }
       m_pDevice->CompositeMask(
           m_pTransformer->result().left, m_pTransformer->result().top,
-          pBitmap->GetWidth(), pBitmap->GetHeight(), pBitmap, m_MaskColor, 0, 0,
-          m_BlendType, m_pClipRgn, m_bRgbByteOrder, m_AlphaFlag,
+          pBitmap->GetWidth(), pBitmap->GetHeight(), pBitmap.get(), m_MaskColor,
+          0, 0, m_BlendType, m_pClipRgn, m_bRgbByteOrder, m_AlphaFlag,
           m_pIccTransform);
     } else {
       if (m_BitmapAlpha != 255)
         pBitmap->MultiplyAlpha(m_BitmapAlpha);
       m_pDevice->CompositeBitmap(
           m_pTransformer->result().left, m_pTransformer->result().top,
-          pBitmap->GetWidth(), pBitmap->GetHeight(), pBitmap, 0, 0, m_BlendType,
-          m_pClipRgn, m_bRgbByteOrder, m_pIccTransform);
+          pBitmap->GetWidth(), pBitmap->GetHeight(), pBitmap.get(), 0, 0,
+          m_BlendType, m_pClipRgn, m_bRgbByteOrder, m_pIccTransform);
     }
     return false;
   }
@@ -1586,11 +1607,11 @@ CFX_BitmapStorer::CFX_BitmapStorer() {
 CFX_BitmapStorer::~CFX_BitmapStorer() {
 }
 
-CFX_RetainPtr<CFX_DIBitmap> CFX_BitmapStorer::Detach() {
+std::unique_ptr<CFX_DIBitmap> CFX_BitmapStorer::Detach() {
   return std::move(m_pBitmap);
 }
 
-void CFX_BitmapStorer::Replace(CFX_RetainPtr<CFX_DIBitmap>&& pBitmap) {
+void CFX_BitmapStorer::Replace(std::unique_ptr<CFX_DIBitmap> pBitmap) {
   m_pBitmap = std::move(pBitmap);
 }
 
@@ -1615,13 +1636,12 @@ bool CFX_BitmapStorer::SetInfo(int width,
                                int height,
                                FXDIB_Format src_format,
                                uint32_t* pSrcPalette) {
-  auto pBitmap = pdfium::MakeRetain<CFX_DIBitmap>();
-  if (!pBitmap->Create(width, height, src_format))
+  m_pBitmap = pdfium::MakeUnique<CFX_DIBitmap>();
+  if (!m_pBitmap->Create(width, height, src_format)) {
+    m_pBitmap.reset();
     return false;
-
+  }
   if (pSrcPalette)
-    pBitmap->SetPalette(pSrcPalette);
-
-  m_pBitmap = std::move(pBitmap);
+    m_pBitmap->SetPalette(pSrcPalette);
   return true;
 }
diff --git a/core/fxge/dib/fx_dib_transform.cpp b/core/fxge/dib/fx_dib_transform.cpp
index 3d8ddf8783..4a1c3ee050 100644
--- a/core/fxge/dib/fx_dib_transform.cpp
+++ b/core/fxge/dib/fx_dib_transform.cpp
@@ -100,7 +100,7 @@ void bicubic_get_pos_weight(int pos_pixel[],
   v_w[3] = SDP_Table[512 - res_y];
 }
 
-FXDIB_Format GetTransformedFormat(const CFX_RetainPtr<CFX_DIBSource>& pDrc) {
+FXDIB_Format GetTransformedFormat(const CFX_DIBSource* pDrc) {
   FXDIB_Format format = pDrc->GetFormat();
   if (pDrc->IsAlphaMask()) {
     format = FXDIB_8bppMask;
@@ -179,7 +179,7 @@ class CFX_BilinearMatrix : public CPDF_FixedMatrix {
   }
 };
 
-CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::SwapXY(
+std::unique_ptr<CFX_DIBitmap> CFX_DIBSource::SwapXY(
     bool bXFlip,
     bool bYFlip,
     const FX_RECT* pDestClip) const {
@@ -189,7 +189,7 @@ CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::SwapXY(
   if (dest_clip.IsEmpty())
     return nullptr;
 
-  auto pTransBitmap = pdfium::MakeRetain<CFX_DIBitmap>();
+  auto pTransBitmap = pdfium::MakeUnique<CFX_DIBitmap>();
   int result_height = dest_clip.Height();
   int result_width = dest_clip.Width();
   if (!pTransBitmap->Create(result_width, result_height, GetFormat()))
@@ -303,14 +303,13 @@ FX_RECT FXDIB_SwapClipBox(FX_RECT& clip,
   return rect;
 }
 
-CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::TransformTo(
+std::unique_ptr<CFX_DIBitmap> CFX_DIBSource::TransformTo(
     const CFX_Matrix* pDestMatrix,
     int& result_left,
     int& result_top,
     uint32_t flags,
-    const FX_RECT* pDestClip) {
-  CFX_RetainPtr<CFX_DIBSource> holder(this);
-  CFX_ImageTransformer transformer(holder, pDestMatrix, flags, pDestClip);
+    const FX_RECT* pDestClip) const {
+  CFX_ImageTransformer transformer(this, pDestMatrix, flags, pDestClip);
   transformer.Start();
   transformer.Continue(nullptr);
   result_left = transformer.result().left;
@@ -318,11 +317,11 @@ CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::TransformTo(
   return transformer.DetachBitmap();
 }
 
-CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::StretchTo(int dest_width,
-                                                     int dest_height,
-                                                     uint32_t flags,
-                                                     const FX_RECT* pClip) {
-  CFX_RetainPtr<CFX_DIBSource> holder(this);
+std::unique_ptr<CFX_DIBitmap> CFX_DIBSource::StretchTo(
+    int dest_width,
+    int dest_height,
+    uint32_t flags,
+    const FX_RECT* pClip) const {
   FX_RECT clip_rect(0, 0, FXSYS_abs(dest_width), FXSYS_abs(dest_height));
   if (pClip)
     clip_rect.Intersect(*pClip);
@@ -334,7 +333,7 @@ CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::StretchTo(int dest_width,
     return Clone(&clip_rect);
 
   CFX_BitmapStorer storer;
-  CFX_ImageStretcher stretcher(&storer, holder, dest_width, dest_height,
+  CFX_ImageStretcher stretcher(&storer, this, dest_width, dest_height,
                                clip_rect, flags);
   if (stretcher.Start())
     stretcher.Continue(nullptr);
@@ -342,11 +341,10 @@ CFX_RetainPtr<CFX_DIBitmap> CFX_DIBSource::StretchTo(int dest_width,
   return storer.Detach();
 }
 
-CFX_ImageTransformer::CFX_ImageTransformer(
-    const CFX_RetainPtr<CFX_DIBSource>& pSrc,
-    const CFX_Matrix* pMatrix,
-    int flags,
-    const FX_RECT* pClip)
+CFX_ImageTransformer::CFX_ImageTransformer(const CFX_DIBSource* pSrc,
+                                           const CFX_Matrix* pMatrix,
+                                           int flags,
+                                           const FX_RECT* pClip)
     : m_pSrc(pSrc),
       m_pMatrix(pMatrix),
       m_pClip(pClip),
@@ -446,7 +444,7 @@ bool CFX_ImageTransformer::Continue(IFX_Pause* pPause) {
     stretch_buf_mask = m_Storer.GetBitmap()->m_pAlphaMask->GetBuffer();
 
   int stretch_pitch = m_Storer.GetBitmap()->GetPitch();
-  auto pTransformed = pdfium::MakeRetain<CFX_DIBitmap>();
+  std::unique_ptr<CFX_DIBitmap> pTransformed(new CFX_DIBitmap);
   FXDIB_Format transformF = GetTransformedFormat(m_Stretcher->source());
   if (!pTransformed->Create(m_result.Width(), m_result.Height(), transformF))
     return false;
@@ -960,6 +958,6 @@ bool CFX_ImageTransformer::Continue(IFX_Pause* pPause) {
   return false;
 }
 
-CFX_RetainPtr<CFX_DIBitmap> CFX_ImageTransformer::DetachBitmap() {
+std::unique_ptr<CFX_DIBitmap> CFX_ImageTransformer::DetachBitmap() {
   return m_Storer.Detach();
 }