Add use counters for lots of DOM APIs.

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

Index: third_party/WebKit/Source/core/html/track/AudioTrackList.idl
diff --git a/third_party/WebKit/Source/core/html/track/AudioTrackList.idl b/third_party/WebKit/Source/core/html/track/AudioTrackList.idl
index 43a321e8b131863b7fb7309c477cd0f63bfb7d4a..4d3bce54be85fa3e1bb6fc2a5786f6b05a707dce 100644
--- a/third_party/WebKit/Source/core/html/track/AudioTrackList.idl
+++ b/third_party/WebKit/Source/core/html/track/AudioTrackList.idl
@@ -8,11 +8,11 @@
     RuntimeEnabled=AudioVideoTracks,
     SetWrapperReferenceFrom=owner,
 ] interface AudioTrackList : EventTarget {
-  readonly attribute unsigned long length;
-  getter AudioTrack (unsigned long index);
-  AudioTrack? getTrackById(DOMString id);
+  [Measure] readonly attribute unsigned long length;
+  [Measure] getter AudioTrack (unsigned long index);
+  [Measure] AudioTrack? getTrackById(DOMString id);
 
-  attribute EventHandler onchange;
-  attribute EventHandler onaddtrack;
-  attribute EventHandler onremovetrack;
+  [Measure] attribute EventHandler onchange;
+  [Measure] attribute EventHandler onaddtrack;
+  [Measure] attribute EventHandler onremovetrack;
 };