Use C++11 range-based loop for core/layout

Source/core/layout/SubtreeLayoutScope.cpp

 /*
  * 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 29 matching lines @@
     : m_root(root)
 {
     RELEASE_ASSERT(m_root.document().view()->isInPerformLayout());
 }
 
 SubtreeLayoutScope::~SubtreeLayoutScope()
 {
     RELEASE_ASSERT(!m_root.needsLayout());
 
 #if ENABLE(ASSERT)
-    for (HashSet<LayoutObject*>::iterator it = m_renderersToLayout.begin(); it != m_renderersToLayout.end(); ++it)
-        (*it)->assertRendererLaidOut();
+    for (auto* renderer : m_renderersToLayout)
+        renderer->assertRendererLaidOut();
 #endif
 }
 
 void SubtreeLayoutScope::setNeedsLayout(LayoutObject* descendant, LayoutInvalidationReasonForTracing reason)
 {
     ASSERT(descendant->isDescendantOf(&m_root));
     descendant->setNeedsLayout(reason, MarkContainerChain, this);
 }
 
 void SubtreeLayoutScope::setChildNeedsLayout(LayoutObject* descendant)
 {
     ASSERT(descendant->isDescendantOf(&m_root));
     descendant->setChildNeedsLayout(MarkContainerChain, this);
 }
 
 void SubtreeLayoutScope::addRendererToLayout(LayoutObject* renderer)
 {
 #if ENABLE(ASSERT)
     m_renderersToLayout.add(renderer);
 #endif
 }
 
 }