Set up clip and scroll parents on the blink side.

Source/core/page/scrolling/ScrollingCoordinator.cpp

Index: Source/core/page/scrolling/ScrollingCoordinator.cpp
diff --git a/Source/core/page/scrolling/ScrollingCoordinator.cpp b/Source/core/page/scrolling/ScrollingCoordinator.cpp
index 68a4ddd5b6043e67311961ce598f018fdc64ee0a..2b685889aec7602a71137b863f61823b9e25ca3e 100644
--- a/Source/core/page/scrolling/ScrollingCoordinator.cpp
+++ b/Source/core/page/scrolling/ScrollingCoordinator.cpp
@@ -491,6 +491,38 @@ void ScrollingCoordinator::touchEventTargetRectsDidChange(const Document*)
     setTouchEventTargetRects(touchEventTargetRects);
 }
 
+void ScrollingCoordinator::updateScrollParentForLayer(RenderLayer* child, RenderLayer* parent)
+{
+    if (!child || !child->backing())
+        return;
+
+    WebLayer* childWebLayer = scrollingWebLayerForGraphicsLayer(child->layerForScrollChild());
+    if (!childWebLayer)
+        return;
+
+    WebLayer* scrollParentWebLayer = 0;
+    if (parent && parent->backing())
+        scrollParentWebLayer = scrollingWebLayerForGraphicsLayer(parent->backing()->parentForSublayers());
+
+    childWebLayer->setScrollParent(scrollParentWebLayer);
+}
+
+void ScrollingCoordinator::updateClipParentForLayer(RenderLayer* child, RenderLayer* parent)
+{
+    if (!child || !child->backing())
+        return;
+
+    WebLayer* childWebLayer = scrollingWebLayerForGraphicsLayer(child->backing()->graphicsLayer());
+    if (!childWebLayer)
+        return;
+
+    WebLayer* clipParentWebLayer = 0;
+    if (parent && parent->backing())
+        clipParentWebLayer = scrollingWebLayerForGraphicsLayer(parent->backing()->parentForSublayers());
+
+    childWebLayer->setClipParent(clipParentWebLayer);
+}
+
 void ScrollingCoordinator::willDestroyRenderLayer(RenderLayer* layer)
 {
     m_layersWithTouchRects.remove(layer);