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

Source/core/layout/line/AbstractInlineTextBox.h

 /*
  * 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 42 matching lines @@
     }
 
     static PassRefPtr<AbstractInlineTextBox> getOrCreate(LayoutText*, InlineTextBox*);
     static void willDestroy(InlineTextBox*);
 
     friend class LayoutText;
     friend class InlineTextBox;
 
 public:
     struct WordBoundaries {
+        ALLOW_ONLY_INLINE_ALLOCATION();
         WordBoundaries(int startIndex, int endIndex) : startIndex(startIndex), endIndex(endIndex) { }
         int startIndex;
         int endIndex;
     };
 
     enum Direction {
         LeftToRight,
         RightToLeft,
         TopToBottom,
         BottomToTop
@@ skipping 22 matching lines @@
     LayoutText* m_layoutText;
     InlineTextBox* m_inlineTextBox;
 
     typedef HashMap<InlineTextBox*, RefPtr<AbstractInlineTextBox>> InlineToAbstractInlineTextBoxHashMap;
     static InlineToAbstractInlineTextBoxHashMap* gAbstractInlineTextBoxMap;
 };
 
 } // namespace blink
 
 #endif // AbstractInlineTextBox_h