Refactoring the way begin frame sources inside scheduler work.

cc/output/begin_frame_args.h

Index: cc/output/begin_frame_args.h
diff --git a/cc/output/begin_frame_args.h b/cc/output/begin_frame_args.h
index 025a4075c25e6b84ab9597dabac7e5c83b34ea1b..62554ca4e774a61596308edda36ed725b3bd5871 100644
--- a/cc/output/begin_frame_args.h
+++ b/cc/output/begin_frame_args.h
@@ -39,6 +39,15 @@ struct CC_EXPORT BeginFrameArgs {
 
   bool IsValid() const { return interval >= base::TimeDelta(); }
 
+  virtual scoped_ptr<base::Value> AsValue() const {
+    scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue);
+    state->SetString("type", "BeginFrameArgs");
+    state->SetInteger("frame_time_us", frame_time.ToInternalValue());
+    state->SetInteger("deadline_us", deadline_.ToInternalValue());
+    state->SetInteger("interval_us", interval_.InMicroseconds());
+    return state.PassAs<base::Value>();
+  }
+
   base::TimeTicks frame_time;
   base::TimeTicks deadline;
   base::TimeDelta interval;