Make Blink stop scheduling its own Layout, and use the compositor's timer instead

Source/core/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 4210 matching lines @@
 bool RenderLayer::hitTest(const HitTestRequest& request, HitTestResult& result)
 {
     return hitTest(request, result.hitTestLocation(), result);
 }
 
 bool RenderLayer::hitTest(const HitTestRequest& request, const HitTestLocation& hitTestLocation, HitTestResult& result)
 {
     ASSERT(isSelfPaintingLayer() || hasSelfPaintingLayerDescendant());
 
     // RenderView should make sure to update layout before entering hit testing
-    ASSERT(!renderer()->frame()->view()->layoutPending());
+    ASSERT(!renderer()->frame()->view()->layoutIsScheduledWithEmbedder());
     ASSERT(!renderer()->document()->renderer()->needsLayout());
 
     LayoutRect hitTestArea = isOutOfFlowRenderFlowThread() ? toRenderFlowThread(renderer())->borderBoxRect() : renderer()->view()->documentRect();
     if (!request.ignoreClipping())
         hitTestArea.intersect(frameVisibleRect(renderer()));
 
     RenderLayer* insideLayer = hitTestLayer(this, 0, request, result, hitTestArea, hitTestLocation, false);
     if (!insideLayer) {
         // We didn't hit any layer. If we are the root layer and the mouse is -- or just was -- down,
         // return ourselves. We do this so mouse events continue getting delivered after a drag has
@@ skipping 2124 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif