Change return types for some rendering Start/Continue methods.

Either return a bool or a CPDF_DIBSource::LoadState. Explain what the
bool return value means.

Change-Id: I6346d0cd61d5faee5290df181cfff3b9e4d5d84e
Reviewed-on: https://pdfium-review.googlesource.com/27851
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

2 files changed, 12 insertions, 7 deletions

diff --git a/core/fpdfapi/page/cpdf_image.cpp b/core/fpdfapi/page/cpdf_image.cpp
index 5f82886a9b..24f58dfeff 100644
--- a/core/fpdfapi/page/cpdf_image.cpp
+++ b/core/fpdfapi/page/cpdf_image.cpp
@@ -351,7 +351,7 @@ bool CPDF_Image::StartLoadDIBSource(CPDF_Dictionary* pFormResource,
   int ret = source->StartLoadDIBSource(m_pDocument.Get(), m_pStream.Get(), true,
                                        pFormResource, pPageResource, bStdCS,
                                        GroupFamily, bLoadMask);
-  if (!ret) {
+  if (ret == 0) {
     m_pDIBSource.Reset();
     return false;
   }
@@ -367,14 +367,14 @@ bool CPDF_Image::StartLoadDIBSource(CPDF_Dictionary* pFormResource,
 bool CPDF_Image::Continue(IFX_PauseIndicator* pPause) {
   RetainPtr<CPDF_DIBSource> pSource = m_pDIBSource.As<CPDF_DIBSource>();
   int ret = pSource->ContinueLoadDIBSource(pPause);
-  if (!ret) {
-    m_pDIBSource.Reset();
-    return false;
-  }
   if (ret == 2)
     return true;
 
-  m_pMask = pSource->DetachMask();
-  m_MatteColor = pSource->GetMatteColor();
+  if (ret == 1) {
+    m_pMask = pSource->DetachMask();
+    m_MatteColor = pSource->GetMatteColor();
+  } else {
+    m_pDIBSource.Reset();
+  }
   return false;
 }
diff --git a/core/fpdfapi/page/cpdf_image.h b/core/fpdfapi/page/cpdf_image.h
index 57cbe94ca2..43011f8822 100644
--- a/core/fpdfapi/page/cpdf_image.h
+++ b/core/fpdfapi/page/cpdf_image.h
@@ -48,12 +48,17 @@ class CPDF_Image : public Retainable {
   void SetJpegImageInline(const RetainPtr<IFX_SeekableReadStream>& pFile);
 
   void ResetCache(CPDF_Page* pPage, const RetainPtr<CFX_DIBitmap>& pDIBitmap);
+
+  // Returns whether to Continue() or not.
   bool StartLoadDIBSource(CPDF_Dictionary* pFormResource,
                           CPDF_Dictionary* pPageResource,
                           bool bStdCS = false,
                           uint32_t GroupFamily = 0,
                           bool bLoadMask = false);
+
+  // Returns whether to Continue() or not.
   bool Continue(IFX_PauseIndicator* pPause);
+
   RetainPtr<CFX_DIBSource> DetachBitmap();
   RetainPtr<CFX_DIBSource> DetachMask();