Plumb in flag to enable antialiased clipping in HTML 5 Canvas

Source/core/html/canvas/CanvasRenderingContext2D.h

Index: Source/core/html/canvas/CanvasRenderingContext2D.h
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.h b/Source/core/html/canvas/CanvasRenderingContext2D.h
index f12666dbf2986157a60b53e59f8ef054391f2f4e..95fe93e616d8e0c2489e5b45e9fe20df0f5ae7f6 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.h
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.h
@@ -69,9 +69,9 @@ typedef WillBeHeapHashMap<String, RefPtrWillBeMember<MutableStylePropertySet> >
 class CanvasRenderingContext2D final: public CanvasRenderingContext, public ScriptWrappable, public CanvasPathMethods {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static PassOwnPtrWillBeRawPtr<CanvasRenderingContext2D> create(HTMLCanvasElement* canvas, const Canvas2DContextAttributes* attrs, bool usesCSSCompatibilityParseMode)
+    static PassOwnPtrWillBeRawPtr<CanvasRenderingContext2D> create(HTMLCanvasElement* canvas, const Canvas2DContextAttributes* attrs, bool usesCSSCompatibilityParseMode, bool antialiasClips)
     {
-        return adoptPtrWillBeNoop(new CanvasRenderingContext2D(canvas, attrs, usesCSSCompatibilityParseMode));
+        return adoptPtrWillBeNoop(new CanvasRenderingContext2D(canvas, attrs, usesCSSCompatibilityParseMode, antialiasClips));
     }
     virtual ~CanvasRenderingContext2D();
 
@@ -297,7 +297,7 @@ private:
         bool m_hasClip;
     };
 
-    CanvasRenderingContext2D(HTMLCanvasElement*, const Canvas2DContextAttributes* attrs, bool usesCSSCompatibilityParseMode);
+    CanvasRenderingContext2D(HTMLCanvasElement*, const Canvas2DContextAttributes* attrs, bool usesCSSCompatibilityParseMode, bool antialiasClips);
 
     State& modifiableState() { ASSERT(!state().m_unrealizedSaveCount); return *m_stateStack.last(); }
     const State& state() const { return *m_stateStack.last(); }
@@ -369,6 +369,7 @@ private:
     WillBeHeapVector<OwnPtrWillBeMember<State> > m_stateStack;
     OwnPtrWillBeMember<HitRegionManager> m_hitRegionManager;
     bool m_usesCSSCompatibilityParseMode;
+    bool m_antialiasClips;
     bool m_hasAlpha;
     bool m_isContextLost;
     bool m_contextRestorable;