Eliminate deferral overhead with canvas to canvas draws

Source/modules/canvas2d/CanvasRenderingContext2D.h

 /*
  * Copyright (C) 2006, 2007, 2009, 2010, 2011, 2012 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 224 matching lines @@
     void setShadow(const FloatSize& offset, float blur, RGBA32 color);
 
     void dispatchContextLostEvent(Timer<CanvasRenderingContext2D>*);
     void dispatchContextRestoredEvent(Timer<CanvasRenderingContext2D>*);
     void tryRestoreContextEvent(Timer<CanvasRenderingContext2D>*);
 
     bool computeDirtyRect(const FloatRect& localBounds, SkIRect*);
     bool computeDirtyRect(const FloatRect& localBounds, const SkIRect& transformedClipBounds, SkIRect*);
     void didDraw(const SkIRect&);
 
-    enum CanvasDeferralMode {
-        AllowDeferredCanvas,
-        ForceImmediateCanvas,
-    };
-
-    SkCanvas* drawingCanvas(CanvasDeferralMode = AllowDeferredCanvas) const;
+    SkCanvas* drawingCanvas() const;
 
     void unwindStateStack();
     void realizeSaves();
 
     void pruneLocalFontCache(size_t targetSize);
     void schedulePruneLocalFontCacheIfNeeded();
 
     bool shouldDrawImageAntialiased(const FloatRect& destRect) const;
 
     template<typename DrawFunc, typename ContainsFunc>
-    bool draw(const DrawFunc&, const ContainsFunc&, CanvasDeferralMode, const SkRect& bounds, CanvasRenderingContext2DState::PaintType, CanvasRenderingContext2DState::ImageType = CanvasRenderingContext2DState::NoImage);
+    bool draw(const DrawFunc&, const ContainsFunc&, const SkRect& bounds, CanvasRenderingContext2DState::PaintType, CanvasRenderingContext2DState::ImageType = CanvasRenderingContext2DState::NoImage);
     void drawPathInternal(const Path&, CanvasRenderingContext2DState::PaintType, SkPath::FillType = SkPath::kWinding_FillType);
     void drawImageInternal(SkCanvas*, CanvasImageSource*, Image*, const FloatRect& srcRect, const FloatRect& dstRect, const SkPaint*);
     void clipInternal(const Path&, const String& windingRuleString);
 
     bool isPointInPathInternal(const Path&, const float x, const float y, const String& windingRuleString);
     bool isPointInStrokeInternal(const Path&, const float x, const float y);
 
     void scrollPathIntoViewInternal(const Path&);
 
     void drawTextInternal(const String&, float x, float y, CanvasRenderingContext2DState::PaintType, float* maxWidth = nullptr);
@@ skipping 49 matching lines @@
     HashMap<String, Font> m_fontsResolvedUsingCurrentStyle;
     bool m_pruneLocalFontCacheScheduled;
     ListHashSet<String> m_fontLRUList;
 };
 
 DEFINE_TYPE_CASTS(CanvasRenderingContext2D, CanvasRenderingContext, context, context->is2d(), context.is2d());
 
 } // namespace blink
 
 #endif // CanvasRenderingContext2D_h