Keep track of multiple layout roots

Source/core/inspector/InspectorInstrumentation.idl

 /*
 * Copyright (C) 2013 Google 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
@@ skipping 189 matching lines @@
     [PageRuntime, Inline=FastReturn]
     void willReleaseScriptContext([Keep] LocalFrame*, ScriptState*);
 
     [AsyncCallTracker, DOMDebugger, Inline=FastReturn]
     InspectorInstrumentationCookie willFireTimer([Keep] ExecutionContext*, int timerId);
 
     [AsyncCallTracker, Debugger, Inline=FastReturn]
     void didFireTimer(const InspectorInstrumentationCookie&);
 
     [Page, Inline=FastReturn]
-    void didLayout(LocalFrame*, LayoutObject* root);
+    void didLayout(LocalFrame*);
 
     [Page, Inline=FastReturn]
     void didScroll(LocalFrame*);
 
     [Page, Inline=FastReturn]
     void didResizeMainFrame(LocalFrame*);
 
     [AsyncCallTracker, Inline=FastReturn]
     void didDispatchXHRLoadendEvent(ExecutionContext*, XMLHttpRequest*);
 
@@ skipping 245 matching lines @@
 interface InspectorCanvasInstrumentation {
 
 #include "bindings/core/v8/ScriptValue.h"
 
     [Canvas]
     ScriptValue wrapCanvas2DRenderingContextForInstrumentation(Document*, const ScriptValue&);
 
     [Canvas]
     ScriptValue wrapWebGLRenderingContextForInstrumentation(Document*, const ScriptValue&);
 }