Set up clip and scroll parents on the blink side.

Source/core/platform/graphics/GraphicsLayer.cpp

Index: Source/core/platform/graphics/GraphicsLayer.cpp
diff --git a/Source/core/platform/graphics/GraphicsLayer.cpp b/Source/core/platform/graphics/GraphicsLayer.cpp
index 60d7c825a54973883ea33f282cae43088462da5d..064ea702b316f23395eb302185fec839670a2e7f 100644
--- a/Source/core/platform/graphics/GraphicsLayer.cpp
+++ b/Source/core/platform/graphics/GraphicsLayer.cpp
@@ -358,8 +358,12 @@ void GraphicsLayer::setOffsetFromRenderer(const IntSize& offset, ShouldSetNeedsD
 
 void GraphicsLayer::paintGraphicsLayerContents(GraphicsContext& context, const IntRect& clip)
 {
-    if (m_client)
+    if (m_client) {
+        TRACE_EVENT_INSTANT2("core,painting", "GraphicsLayer::paintGraphicsLayerContents",

[enne (OOO), 2013/08/22 20:54:30]

I think we already are tracing this from the compositor side.

+            "width", clip.width(), "height", clip.height());
+
         m_client->paintContents(this, context, m_paintingPhase, clip);
+    }
 }
 
 String GraphicsLayer::animationNameForTransition(AnimatedPropertyID property)
@@ -1302,6 +1306,12 @@ void GraphicsLayer::notifyAnimationFinished(double)
 
 void GraphicsLayer::didScroll()
 {
+    TRACE_EVENT1(
+        "impl-scroll",
+        "GraphicsLayer::didScroll",
+        "layerId",
+        m_layer->layer()->id());
+
     if (m_scrollableArea)
         m_scrollableArea->scrollToOffsetWithoutAnimation(m_scrollableArea->minimumScrollPosition() + toIntSize(m_layer->layer()->scrollPosition()));
 }