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

Source/core/editing/CompositionUnderline.h

 /*
  * Copyright (C) 2006, 2007, 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (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 CompositionUnderline_h
 #define CompositionUnderline_h
 
 #include "platform/graphics/Color.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
 struct CompositionUnderline {
+    ALLOW_ONLY_INLINE_ALLOCATION();
     CompositionUnderline()
         : startOffset(0)
         , endOffset(0)
         , color(Color::transparent)
         , thick(false)
         , backgroundColor(Color::transparent) { }
 
     CompositionUnderline(unsigned s, unsigned e, const Color& c, bool t, const Color& bc)
         : startOffset(s)
         , endOffset(e)
         , color(c)
         , thick(t)
         , backgroundColor(bc) { }
 
     unsigned startOffset;
     unsigned endOffset;
     Color color;
     bool thick;
     Color backgroundColor;
 };
 
 } // namespace blink
 
 #endif // CompositionUnderline_h