Add UseCounters for some (now) non-standard CSS APIs

Source/core/css/CSSKeyframesRule.idl

Index: Source/core/css/CSSKeyframesRule.idl
diff --git a/Source/core/css/CSSKeyframesRule.idl b/Source/core/css/CSSKeyframesRule.idl
index 93f3d537baab891f1750a0becbf1036f6ef04d61..9176870da40f3ed19e4879264bb387cf39744aea 100644
--- a/Source/core/css/CSSKeyframesRule.idl
+++ b/Source/core/css/CSSKeyframesRule.idl
@@ -32,8 +32,8 @@ interface CSSKeyframesRule : CSSRule {
     readonly attribute CSSRuleList cssRules;
 
     [ImplementedAs=item, NotEnumerable] getter CSSKeyframeRule (unsigned long index);
-    void insertRule([Default=Undefined] optional DOMString rule);
-    [ImplementedAs=insertRule] void appendRule([Default=Undefined] optional DOMString rule);
+    [MeasureAs=CSSKeyframesRuleInsertRule] void insertRule([Default=Undefined] optional DOMString rule);
+    [ImplementedAs=insertRule, MeasureAs=CSSKeyframesRuleAppendRule] void appendRule([Default=Undefined] optional DOMString rule);
     void deleteRule([Default=Undefined] optional DOMString key);
     CSSKeyframeRule findRule([Default=Undefined] optional DOMString key);
 };