Offset rects by origin when projecting from composited to graphics layer.

Source/core/testing/Internals.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 1292 matching lines @@
 
     unsigned count = 0;
     for (TouchEventTargetSet::const_iterator iter = touchHandlers->begin(); iter != touchHandlers->end(); ++iter)
         count += iter->value;
     return count;
 }
 
 static RenderLayer* findRenderLayerForGraphicsLayer(RenderLayer* searchRoot, GraphicsLayer* graphicsLayer, IntSize* layerOffset, String* layerType)
 {
     *layerOffset = IntSize();
-    if (searchRoot->hasCompositedLayerMapping() && graphicsLayer == searchRoot->compositedLayerMapping()->mainGraphicsLayer())
+    if (searchRoot->hasCompositedLayerMapping() && graphicsLayer == searchRoot->compositedLayerMapping()->mainGraphicsLayer()) {
+        CompositedLayerMappingPtr compositedLayerMapping = searchRoot->compositedLayerMapping();
+        LayoutSize offset = compositedLayerMapping->contentOffsetInCompositingLayer();
+        *layerOffset = IntSize(offset.width(), offset.height());
         return searchRoot;
+    }
 
     GraphicsLayer* layerForScrolling = searchRoot->scrollableArea() ? searchRoot->scrollableArea()->layerForScrolling() : 0;
     if (graphicsLayer == layerForScrolling) {
         *layerType = "scrolling";
         return searchRoot;
     }
 
     if (searchRoot->compositingState() == PaintsIntoGroupedBacking) {
         GraphicsLayer* squashingLayer = searchRoot->groupedMapping()->squashingLayer();
         if (graphicsLayer == squashingLayer) {
@@ skipping 1046 matching lines @@
 String Internals::textSurroundingNode(Node* node, int x, int y, unsigned long maxLength)
 {
     if (!node)
         return String();
     blink::WebPoint point(x, y);
     SurroundingText surroundingText(VisiblePosition(node->renderer()->positionForPoint(static_cast<IntPoint>(point))), maxLength);
     return surroundingText.content();
 }
 
 }