DevTools: add "Jump to Relayout Boundary" context menu item in Elements panel

Source/core/rendering/RenderObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 3288 matching lines @@
     static const AffineTransform identity;
     return identity;
 }
 
 bool RenderObject::nodeAtFloatPoint(const HitTestRequest&, HitTestResult&, const FloatPoint&, HitTestAction)
 {
     ASSERT_NOT_REACHED();
     return false;
 }
 
+bool RenderObject::isRelayoutBoundaryForInstrumentation() const
+{
+    return objectIsRelayoutBoundary(this);
+}
+
 } // namespace WebCore
 
 #ifndef NDEBUG
 
 void showTree(const WebCore::RenderObject* object)
 {
     if (object)
         object->showTreeForThis();
 }
 
@@ skipping 12 matching lines @@
 {
     if (object1) {
         const WebCore::RenderObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showRenderTreeAndMark(object1, "*", object2, "-", 0);
     }
 }
 
 #endif