Keep track of multiple layout roots

Source/core/inspector/InspectorPageAgent.cpp

 /*
  * Copyright (C) 2011 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 1179 matching lines @@
         Color(0, 0x5F, 0, 0x3F),
         Color(0, 0xAF, 0, 0x3F),
         Color(0, 0xFF, 0, 0x3F),
     };
 
     LayoutRect inflatedRect(rect);
     inflatedRect.inflate(-1);
     m_overlay->drawOutline(context, inflatedRect, colors[colorSelector++ % WTF_ARRAY_LENGTH(colors)]);
 }
 
-void InspectorPageAgent::didLayout(LayoutObject*)
+void InspectorPageAgent::didLayout()
 {
     if (!m_enabled)
         return;
     m_overlay->update();
     viewportChanged();
 }
 
 void InspectorPageAgent::didScroll()
 {
     if (m_enabled)
@@ skipping 285 matching lines @@
 DEFINE_TRACE(InspectorPageAgent)
 {
     visitor->trace(m_page);
     visitor->trace(m_injectedScriptManager);
     visitor->trace(m_inspectorResourceContentLoader);
     InspectorBaseAgent::trace(visitor);
 }
 
 } // namespace blink