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

Source/core/layout/ScrollAlignment.h

 /*
  * Copyright (C) 2003, 2009 Apple Inc.  All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 27 matching lines @@
  * deletingthe provisions above and replace them with the notice and
  * other provisions required by the MPL or the GPL, as the case may be.
  * If you do not delete the provisions above, a recipient may use your
  * version of this file under any of the LGPL, the MPL or the GPL.
  */
 
 #ifndef ScrollAlignment_h
 #define ScrollAlignment_h
 
 #include "core/CoreExport.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
 enum ScrollAlignmentBehavior {
     ScrollAlignmentNoScroll,
     ScrollAlignmentCenter,
     ScrollAlignmentTop,
     ScrollAlignmentBottom,
     ScrollAlignmentLeft,
     ScrollAlignmentRight,
     ScrollAlignmentClosestEdge
 };
 
 class LayoutRect;
 
 struct CORE_EXPORT ScrollAlignment {
+    STACK_ALLOCATED();
     static ScrollAlignmentBehavior getVisibleBehavior(const ScrollAlignment& s) { return s.m_rectVisible; }
     static ScrollAlignmentBehavior getPartialBehavior(const ScrollAlignment& s) { return s.m_rectPartial; }
     static ScrollAlignmentBehavior getHiddenBehavior(const ScrollAlignment& s) { return s.m_rectHidden; }
 
     // FIXME: This function should probably go somewhere else but where?
     static LayoutRect getRectToExpose(const LayoutRect& visibleRect, const LayoutRect& exposeRect, const ScrollAlignment& alignX, const ScrollAlignment& alignY);
 
     static const ScrollAlignment alignCenterIfNeeded;
     static const ScrollAlignment alignToEdgeIfNeeded;
     static const ScrollAlignment alignCenterAlways;
     static const ScrollAlignment alignTopAlways;
     static const ScrollAlignment alignBottomAlways;
 
     ScrollAlignmentBehavior m_rectVisible;
     ScrollAlignmentBehavior m_rectHidden;
     ScrollAlignmentBehavior m_rectPartial;
 };
 
 
 } // namespace blink
 
 #endif // ScrollAlignment_h