Make classes and structures in Source/core/animation fast-allocated.

Source/core/animation/LengthPropertyFunctions.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef LengthPropertyFunctions_h
 #define LengthPropertyFunctions_h
 
 #include "core/CSSPropertyNames.h"
 #include "core/CSSValueKeywords.h"
 #include "platform/Length.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
 class ComputedStyle;
 
 class LengthPropertyFunctions {
+    STATIC_ONLY(LengthPropertyFunctions);
 public:
     typedef void (ComputedStyle::*LengthSetter)(const Length&);
 
     static ValueRange valueRange(CSSPropertyID);
     static bool getPixelsForKeyword(CSSPropertyID, CSSValueID, double& resultPixels);
     static bool getLength(CSSPropertyID, const ComputedStyle&, Length& result);
     static bool getInitialLength(CSSPropertyID, Length& result);
 };
 
 } // namespace blink
 
 #endif // LengthPropertyFunctions_h