Avoid passing pointers by reference in core.

This gets rid of most core/ non-const ref passing, either by passing by
pointer-to-pointer instead, or by returning std::pair.

Change-Id: Id7bdc355a1a725a05f9fa2f1e982ca8c975beef1
Reviewed-on: https://pdfium-review.googlesource.com/19030
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/core/fxcodec/codec/ccodec_pngmodule.h b/core/fxcodec/codec/ccodec_pngmodule.h
index 121e646a86..847f67e8eb 100644
--- a/core/fxcodec/codec/ccodec_pngmodule.h
+++ b/core/fxcodec/codec/ccodec_pngmodule.h
@@ -28,7 +28,11 @@ class CCodec_PngModule {
                                int pass,
                                int* color_type,
                                double* gamma) = 0;
-    virtual bool PngAskScanlineBuf(int line, uint8_t*& src_buf) = 0;
+
+    // Returns true on success. |pSrcBuf| will be set if this succeeds.
+    // |pSrcBuf| does not take ownership of the buffer.
+    virtual bool PngAskScanlineBuf(int line, uint8_t** pSrcBuf) = 0;
+
     virtual void PngFillScanlineBufCompleted(int pass, int line) = 0;
   };