Replace RefPtrs with raw pointers (imageFromNode in Editor.cpp)

third_party/WebKit/Source/core/html/HTMLCanvasElement.h

Index: third_party/WebKit/Source/core/html/HTMLCanvasElement.h
diff --git a/third_party/WebKit/Source/core/html/HTMLCanvasElement.h b/third_party/WebKit/Source/core/html/HTMLCanvasElement.h
index 37c79ec851a2c8a9cf5b8d3b057ce0cb3554f6fd..3b9420e400536b6e232c63c67dc6a20888addd1f 100644
--- a/third_party/WebKit/Source/core/html/HTMLCanvasElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLCanvasElement.h
@@ -132,7 +132,7 @@ public:
 
     void ensureUnacceleratedImageBuffer();
     ImageBuffer* buffer() const;
-    PassRefPtr<Image> copiedImage(SourceDrawingBuffer, AccelerationHint) const;
+    Image* copiedImage(SourceDrawingBuffer, AccelerationHint) const;
     void clearCopiedImage();
 
     SecurityOrigin* getSecurityOrigin() const;
@@ -238,6 +238,8 @@ private:
 
     String toDataURLInternal(const String& mimeType, const double& quality, SourceDrawingBuffer) const;
 
+    Image* ensureTransparentImage() const;
+
     HeapHashSet<WeakMember<CanvasDrawListener>> m_listeners;
 
     IntSize m_size;
@@ -261,6 +263,8 @@ private:
 
     // Used for OffscreenCanvas that controls this HTML canvas element
     std::unique_ptr<CanvasSurfaceLayerBridge> m_surfaceLayerBridge;
+
+    mutable RefPtr<Image> m_transparentImage;

[haraken, 2016/07/06 12:46:44]

Why do we need to keep alive the image after copiedImage() returns?

This CL is going to unnecessarily prolong the lifetime of m_transparentImage,
which doesn't seem like a right thing to do to me.

[hajimehoshi, 2016/07/07 10:53:07]

Hmm, I agree.

Do you think it'd make sense if m_transparentImage lives only when m_context is
null?

[haraken, 2016/07/07 11:00:56]

I don't fully understand what problem you're trying to solve.

I don't think HTMLCanvasElement should hold m_transparentImage.
HTMLCanvasElement is just responsible for creating the transparent image and
return the image to someone else. If the someone wants to hold the reference,
the someone should do that.

So the current design looks reasonable to me. HTMLCanvasElement returns a
PassRefPtr to pass the ownership. The receiver is responsible for handling the
ownership. In this particular case, the receiver doesn't need to hold the
reference, so the receiver just drops it immediately. This design doesn't look
strange to me.

 };
 
 } // namespace blink