Plumb in flag to enable antialiased clipping in HTML 5 Canvas

Source/core/html/HTMLCanvasElement.cpp

Index: Source/core/html/HTMLCanvasElement.cpp
diff --git a/Source/core/html/HTMLCanvasElement.cpp b/Source/core/html/HTMLCanvasElement.cpp
index 750e1fd6f566cc87902c094d100111be19cd0511..d5c6727732793610700e82ded45e4f3c79dd5774 100644
--- a/Source/core/html/HTMLCanvasElement.cpp
+++ b/Source/core/html/HTMLCanvasElement.cpp
@@ -168,7 +168,12 @@ CanvasRenderingContext* HTMLCanvasElement::getContext(const String& type, Canvas
             return 0;
         if (!m_context) {
             blink::Platform::current()->histogramEnumeration("Canvas.ContextType", Context2d, ContextTypeCount);
-            m_context = CanvasRenderingContext2D::create(this, static_cast<Canvas2DContextAttributes*>(attrs), document().inQuirksMode());
+
+            bool antialiasClips = false;
+            if (document().settings() && document().settings()->antialiasedClips2dCanvasEnabled())
+                antialiasClips = true;
+
+            m_context = CanvasRenderingContext2D::create(this, static_cast<Canvas2DContextAttributes*>(attrs), document().inQuirksMode(), antialiasClips);

[Justin Novosad, 2014/10/14 14:46:43]

Me wonders if we should just pass 'this' or 'document()' to
CanvasRenderingContext2D::create so that it can extract whatever settings it
needs (quirksMode & antialias clips).

[robertphillips, 2014/10/16 13:24:18]

Done - passed in document.

             setNeedsCompositingUpdate();
         }
         return m_context.get();