Add use counters for lots of DOM APIs.

third_party/WebKit/Source/core/events/MutationEvent.idl

Index: third_party/WebKit/Source/core/events/MutationEvent.idl
diff --git a/third_party/WebKit/Source/core/events/MutationEvent.idl b/third_party/WebKit/Source/core/events/MutationEvent.idl
index c377ae55fd9616fa4937121c1844059230234af8..d64f253494d31a3286de1a4b3ae67d95a169f791 100644
--- a/third_party/WebKit/Source/core/events/MutationEvent.idl
+++ b/third_party/WebKit/Source/core/events/MutationEvent.idl
@@ -25,11 +25,11 @@ interface MutationEvent : Event {
     const unsigned short ADDITION     = 2;
     const unsigned short REMOVAL      = 3;
 
-    readonly attribute Node?          relatedNode;
-    readonly attribute DOMString      prevValue;
-    readonly attribute DOMString      newValue;
-    readonly attribute DOMString      attrName;
-    readonly attribute unsigned short attrChange;
+    [Measure] readonly attribute Node?          relatedNode;
+    [Measure] readonly attribute DOMString      prevValue;
+    [Measure] readonly attribute DOMString      newValue;
+    [Measure] readonly attribute DOMString      attrName;
+    [Measure] readonly attribute unsigned short attrChange;
     // TODO(foolip): None of the initMutationEvent() arguments should be optional.
     [Measure] void initMutationEvent([Default=Undefined] optional DOMString type,
                                      [Default=Undefined] optional boolean bubbles,