Make classes and structures in core/editing fast-allocated.

Source/core/editing/RenderedPosition.h

 /*
  * 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 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef RenderedPosition_h
 #define RenderedPosition_h
 
 #include "core/CoreExport.h"
 #include "core/editing/Position.h"
 #include "core/layout/line/InlineBox.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
 class LayoutUnit;
 class LayoutObject;
 class VisiblePosition;
 struct CompositedSelectionBound;
 
 class RenderedPosition {
+    STACK_ALLOCATED();
 public:
     RenderedPosition();
     explicit RenderedPosition(const VisiblePosition&);
     RenderedPosition(const Position&, TextAffinity);
     RenderedPosition(const PositionInComposedTree&, TextAffinity);
     bool isEquivalent(const RenderedPosition&) const;
 
     bool isNull() const { return !m_layoutObject; }
     RootInlineBox* rootBox() { return m_inlineBox ? &m_inlineBox->root() : 0; }
 
@@ skipping 54 matching lines @@
     , m_prevLeafChild(uncachedInlineBox())
     , m_nextLeafChild(uncachedInlineBox())
 {
 }
 
 CORE_EXPORT bool layoutObjectContainsPosition(LayoutObject*, const Position&);
 
 };
 
 #endif // RenderedPosition_h