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

Source/core/layout/line/LineWidth.h

 /*
  * Copyright (C) 2013 Adobe Systems Incorporated. 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.
@@ skipping 14 matching lines @@
  * 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 LineWidth_h
 #define LineWidth_h
 
 #include "core/layout/api/LineLayoutBlockFlow.h"
 #include "platform/LayoutUnit.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
 class FloatingObject;
 class LineLayoutRubyRun;
 
 enum IndentTextOrNot { DoNotIndentText, IndentText };
 enum WhitespaceTreatment { ExcludeWhitespace, IncludeWhitespace };
 
 class LineWidth {
+    STACK_ALLOCATED();
 public:
     LineWidth(LineLayoutBlockFlow, bool isFirstLine, IndentTextOrNot shouldIndentText);
 
     bool fitsOnLine() const { return currentWidth() <= (m_availableWidth + LayoutUnit::epsilon()); }
     bool fitsOnLine(float extra) const { return currentWidth() + extra <= (m_availableWidth + LayoutUnit::epsilon()); }
     bool fitsOnLine(float extra, WhitespaceTreatment whitespaceTreatment) const
     {
         return currentWidth() - (whitespaceTreatment == ExcludeWhitespace ? trailingWhitespaceWidth() : 0) + extra <= (m_availableWidth + LayoutUnit::epsilon());
     }
 
@@ skipping 27 matching lines @@
     float m_left;
     float m_right;
     float m_availableWidth;
     bool m_isFirstLine;
     IndentTextOrNot m_shouldIndentText;
 };
 
 }
 
 #endif // LineWidth_h