Eliminate deferral overhead with canvas to canvas draws

Source/platform/graphics/Canvas2DLayerBridge.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 47 matching lines @@
     // WebExternalTextureLayerClient implementation.
     bool prepareMailbox(WebExternalTextureMailbox*, WebExternalBitmap*) override;
     void mailboxReleased(const WebExternalTextureMailbox&, bool lostResource) override;
 
     // ImageBufferSurface implementation
     void finalizeFrame(const FloatRect &dirtyRect);
     void willWritePixels();
     void willOverwriteAllPixels();
     void willOverwriteCanvas();
     SkCanvas* canvas();
-    SkCanvas* immediateCanvas();
+    void disableDeferral();
     bool checkSurfaceValid();
     bool restoreSurface();
     WebLayer* layer() const;
     bool isAccelerated() const { return true; }
     void setFilterQuality(SkFilterQuality);
     void setIsHidden(bool);
     void setImageBuffer(ImageBuffer*);
     void didDraw();
     bool writePixels(const SkImageInfo&, const void* pixels, size_t rowBytes, int x, int y);
     void flush();
@@ skipping 22 matching lines @@
     ImageBuffer* m_imageBuffer;
     int m_msaaSampleCount;
     size_t m_bytesAllocated;
     bool m_haveRecordedDrawCommands;
     int m_framesPending;
     int m_framesSinceMailboxRelease;
     bool m_destructionInProgress;
     bool m_rateLimitingEnabled;
     SkFilterQuality m_filterQuality;
     bool m_isHidden;
+    bool m_isDeferralEnabled;
 
     friend class Canvas2DLayerBridgeTest;
 
     struct MailboxInfo {
         WebExternalTextureMailbox m_mailbox;
         RefPtr<SkImage> m_image;
         RefPtr<Canvas2DLayerBridge> m_parentLayerBridge;
 
         MailboxInfo(const MailboxInfo&);
         MailboxInfo() {}
     };
 
     uint32_t m_lastImageId;
 
     enum {
         // We should normally not have more that two active mailboxes at a time,
         // but sometime we may have three due to the async nature of mailbox handling.
         MaxActiveMailboxes = 3,
     };
 
     Deque<MailboxInfo, MaxActiveMailboxes> m_mailboxes;
     GLenum m_lastFilter;
     OpacityMode m_opacityMode;
     IntSize m_size;
 };
 
 } // namespace blink
 
 #endif