Introduce typeface cache in blink::FontCache

third_party/WebKit/Source/platform/fonts/FontDataCache.h

Index: third_party/WebKit/Source/platform/fonts/FontDataCache.h
diff --git a/third_party/WebKit/Source/platform/fonts/FontDataCache.h b/third_party/WebKit/Source/platform/fonts/FontDataCache.h
index 3652e0350b1479675a59fdeb504e315eeb6a056f..4f011113baedffcbabb352d9b536ffd7dfaaacaf 100644
--- a/third_party/WebKit/Source/platform/fonts/FontDataCache.h
+++ b/third_party/WebKit/Source/platform/fonts/FontDataCache.h
@@ -60,7 +60,7 @@ struct FontDataCacheKeyTraits : WTF::GenericHashTraits<FontPlatformData> {
     static const bool emptyValueIsZero = true;
     static const FontPlatformData& emptyValue()
     {
-        DEFINE_STATIC_LOCAL(FontPlatformData, key, (0.f, false, false));
+        DEFINE_STATIC_LOCAL(FontPlatformData, key, (false, false));
         return key;
     }
     static void constructDeletedValue(FontPlatformData& slot, bool)
@@ -79,7 +79,7 @@ class FontDataCache {
 public:
     FontDataCache() { }
 
-    PassRefPtr<SimpleFontData> get(const FontPlatformData*, ShouldRetain = Retain);
+    PassRefPtr<SimpleFontData> get(const FontPlatformData*, float fontSize, ShouldRetain = Retain);
     bool contains(const FontPlatformData*) const;
     void release(const SimpleFontData*);
 
@@ -94,7 +94,8 @@ public:
 private:
     bool purgeLeastRecentlyUsed(int count);
 
-    typedef HashMap<FontPlatformData, std::pair<RefPtr<SimpleFontData>, unsigned>, FontDataCacheKeyHash, FontDataCacheKeyTraits> Cache;
+    typedef HashMap<float, std::pair<RefPtr<SimpleFontData>, unsigned>> InnerCache;
+    typedef HashMap<FontPlatformData, InnerCache, FontDataCacheKeyHash, FontDataCacheKeyTraits> Cache;
     Cache m_cache;
     ListHashSet<RefPtr<SimpleFontData>> m_inactiveFontData;
 };