GraphicsContext culling support.

Source/platform/graphics/GraphicsContext.cpp

Index: Source/platform/graphics/GraphicsContext.cpp
diff --git a/Source/platform/graphics/GraphicsContext.cpp b/Source/platform/graphics/GraphicsContext.cpp
index 5f8fc1109c2669579e506d99d1ce31415100ce46..5d699d8ee99a594b1eaccfe93f19279b1871c1f3 100644
--- a/Source/platform/graphics/GraphicsContext.cpp
+++ b/Source/platform/graphics/GraphicsContext.cpp
@@ -1525,6 +1525,25 @@ void GraphicsContext::clipRRect(const SkRRect& rect, AntiAliasingMode aa, SkRegi
     m_canvas->clipRRect(rect, op, aa == AntiAliased);
 }
 
+void GraphicsContext::beginCull(const FloatRect& rect)
+{
+    if (paintingDisabled())
+        return;
+
+    realizeCanvasSave(SkCanvas::kMatrixClip_SaveFlag);
+    m_canvas->pushCull(rect);
+}
+
+void GraphicsContext::endCull()
+{
+    if (paintingDisabled())
+        return;
+
+    realizeCanvasSave(SkCanvas::kMatrixClip_SaveFlag);
+
+    m_canvas->popCull();
+}
+
 void GraphicsContext::rotate(float angleInRadians)
 {
     if (paintingDisabled())