Add use counters for lots of DOM APIs.

third_party/WebKit/Source/core/html/track/VideoTrackList.idl

Index: third_party/WebKit/Source/core/html/track/VideoTrackList.idl
diff --git a/third_party/WebKit/Source/core/html/track/VideoTrackList.idl b/third_party/WebKit/Source/core/html/track/VideoTrackList.idl
index 0651763d569d93aead56f5e706b7cabd4635202a..e0f6a9ac1cc3189d8fa45d1bea478423aa22ec57 100644
--- a/third_party/WebKit/Source/core/html/track/VideoTrackList.idl
+++ b/third_party/WebKit/Source/core/html/track/VideoTrackList.idl
@@ -8,12 +8,12 @@
     RuntimeEnabled=AudioVideoTracks,
     SetWrapperReferenceFrom=owner,
 ] interface VideoTrackList : EventTarget {
-  readonly attribute unsigned long length;
-  getter VideoTrack (unsigned long index);
-  VideoTrack? getTrackById(DOMString id);
-  readonly attribute long selectedIndex;
+  [Measure] readonly attribute unsigned long length;
+  [Measure] getter VideoTrack (unsigned long index);
+  [Measure] VideoTrack? getTrackById(DOMString id);
+  [Measure] readonly attribute long selectedIndex;
 
-  attribute EventHandler onchange;
-  attribute EventHandler onaddtrack;
-  attribute EventHandler onremovetrack;
+  [Measure] attribute EventHandler onchange;
+  [Measure] attribute EventHandler onaddtrack;
+  [Measure] attribute EventHandler onremovetrack;
 };