NOT FOR SUBMIT: use counters for jdm@

third_party/WebKit/Source/core/streams/UnderlyingSourceBase.idl

Index: third_party/WebKit/Source/core/streams/UnderlyingSourceBase.idl
diff --git a/third_party/WebKit/Source/core/streams/UnderlyingSourceBase.idl b/third_party/WebKit/Source/core/streams/UnderlyingSourceBase.idl
index 2b05a8d7038eec5fb591788a83dd9a1424429d2c..ecc54926cc14f10cd56287ebd3aa2cb27f994847 100644
--- a/third_party/WebKit/Source/core/streams/UnderlyingSourceBase.idl
+++ b/third_party/WebKit/Source/core/streams/UnderlyingSourceBase.idl
@@ -13,9 +13,9 @@
     NoInterfaceObject,
 ]
 interface UnderlyingSourceBase {
-    [CallWith=ScriptState, ImplementedAs=startWrapper] Promise<void> start(any stream);
-    [CallWith=ScriptState] Promise<void> pull();
-    [CallWith=ScriptState, ImplementedAs=cancelWrapper] Promise<void> cancel([Default=Undefined] optional any reason);
+  [Measure, CallWith=ScriptState, ImplementedAs=startWrapper] Promise<void> start(any stream);
+  [Measure, CallWith=ScriptState] Promise<void> pull();
+  [Measure, CallWith=ScriptState, ImplementedAs=cancelWrapper] Promise<void> cancel([Default=Undefined] optional any reason);
 
     void notifyLockAcquired();
     void notifyLockReleased();