WIP: Adjust externally allocated memory when ImageBitmap is transferred

third_party/WebKit/Source/platform/graphics/StaticBitmapImage.h

Index: third_party/WebKit/Source/platform/graphics/StaticBitmapImage.h
diff --git a/third_party/WebKit/Source/platform/graphics/StaticBitmapImage.h b/third_party/WebKit/Source/platform/graphics/StaticBitmapImage.h
index 2a203df8d7516239f60e4ef6d6dd298250e4811f..5e538e78d2214878b9f1ccfe1585befa9958fb59 100644
--- a/third_party/WebKit/Source/platform/graphics/StaticBitmapImage.h
+++ b/third_party/WebKit/Source/platform/graphics/StaticBitmapImage.h
@@ -39,6 +39,8 @@ class PLATFORM_EXPORT StaticBitmapImage : public Image {
   virtual bool hasMailbox() { return false; }
 
   virtual void transfer() {}
+  virtual void registerExternalAllocationWithCurrentContext() {}
+  virtual void unregisterExternalAllocationWithCurrentContext() {}

[Justin Novosad, 2017/04/04 16:15:15]

Would be better to register/unregister right here in StaticBitmapImage instead
of delegating to subclass via virtual.  Rationale: AcceleratedStaticBitmapImage
should also trigger GCs,  even though it does not technically consume RAM, GPU
memory is still a precious resource that needs to be freed.

 
   // Methods overrided by AcceleratedStaticBitmapImage only
   virtual void copyToTexture(WebGraphicsContext3DProvider*,