Remove m_keyFrameRulesMap in StyleResolver

Source/core/css/resolver/StyleResolver.h

Index: Source/core/css/resolver/StyleResolver.h
diff --git a/Source/core/css/resolver/StyleResolver.h b/Source/core/css/resolver/StyleResolver.h
index fa5e8d789d5ed7b75f0735cc8e4e0e890e51c80d..f1c14a4b5a3275e93f8682d2361a03d19fd4f2a4 100644
--- a/Source/core/css/resolver/StyleResolver.h
+++ b/Source/core/css/resolver/StyleResolver.h
@@ -264,10 +264,6 @@ private:
 
     Document& document() { return *m_document; }
 
-    // FIXME: This likely belongs on RuleSet.
-    typedef WillBeHeapHashMap<StringImpl*, RefPtrWillBeMember<StyleRuleKeyframes> > KeyframesRuleMap;
-    KeyframesRuleMap m_keyframesRuleMap;
-
     static RenderStyle* s_styleNotYetAvailable;
 
     void cacheBorderAndBackground();