Introduce FontCache content scaling

third_party/WebKit/Source/platform/fonts/FontCacheKey.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:
  *
  * 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
@@ skipping 67 matching lines @@
     bool isHashTableDeletedValue() const
     {
         return m_fontSize == hashTableDeletedSize();
     }
 
     static unsigned precisionMultiplier()
     {
         return s_fontSizePrecisionMultiplier;
     }
 
+    void clearFontSize()
+    {
+        m_fontSize = 0;
+    }
+
 private:
     static unsigned hashTableDeletedSize()
     {
         return 0xFFFFFFFFU;
     }
 
     FontFaceCreationParams m_creationParams;
     unsigned m_fontSize;
     unsigned m_options;
 };
@@ skipping 13 matching lines @@
     static const bool safeToCompareToEmptyOrDeleted = true;
 };
 
 struct FontCacheKeyTraits : WTF::SimpleClassHashTraits<FontCacheKey> {
     STATIC_ONLY(FontCacheKeyTraits);
 };
 
 } // namespace blink
 
 #endif // FontCacheKey_h