Add use counters for lots of DOM APIs.

third_party/WebKit/Source/core/html/track/vtt/VTTCue.idl

Index: third_party/WebKit/Source/core/html/track/vtt/VTTCue.idl
diff --git a/third_party/WebKit/Source/core/html/track/vtt/VTTCue.idl b/third_party/WebKit/Source/core/html/track/vtt/VTTCue.idl
index cf15a6528f0612a2203319c00987c944a4b9c602..bcd0f73c41476a6f1f19f3d8ba96d7147c7e8cb9 100644
--- a/third_party/WebKit/Source/core/html/track/vtt/VTTCue.idl
+++ b/third_party/WebKit/Source/core/html/track/vtt/VTTCue.idl
@@ -42,14 +42,14 @@ enum AlignSetting { "start", "middle", "end", "left", "right" };
 ] interface VTTCue : TextTrackCue {
     // TODO(foolip): regionId has been replaced by a region attribute.
     [RuntimeEnabled=WebVTTRegions] attribute DOMString regionId;
-    attribute DirectionSetting vertical;
-    attribute boolean snapToLines;
-    attribute (double or AutoKeyword) line;
+    [Measure] attribute DirectionSetting vertical;
+    [Measure] attribute boolean snapToLines;
+    [Measure] attribute (double or AutoKeyword) line;
     // attribute LineAlignSetting lineAlign;
-    [RaisesException=Setter] attribute (double or AutoKeyword) position;
+  [Measure, RaisesException=Setter] attribute (double or AutoKeyword) position;
     // attribute PositionAlignSetting positionAlign;
-    [RaisesException=Setter] attribute double size;
-    attribute AlignSetting align;
-    attribute DOMString text;
-    DocumentFragment getCueAsHTML();
+  [Measure, RaisesException=Setter] attribute double size;
+    [Measure] attribute AlignSetting align;
+    [Measure] attribute DOMString text;
+    [Measure] DocumentFragment getCueAsHTML();
 };