cc: Also trace the scheduler client state

cc/scheduler/scheduler.h

Index: cc/scheduler/scheduler.h
diff --git a/cc/scheduler/scheduler.h b/cc/scheduler/scheduler.h
index 34473ad90db7753bfab2bd2e67c4cdc5959fabb6..5dac4850a9040f3edb8dba6b5680145f8ec48d01 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -102,7 +102,7 @@ class CC_EXPORT Scheduler {
 
   bool WillDrawIfNeeded() const;
 
-  base::TimeTicks AnticipatedDrawTime();
+  base::TimeTicks AnticipatedDrawTime() const;
 
   base::TimeTicks LastBeginImplFrameTime();
 
@@ -110,9 +110,7 @@ class CC_EXPORT Scheduler {
   void OnBeginImplFrameDeadline();
   void PollForAnticipatedDrawTriggers();
 
-  scoped_ptr<base::Value> StateAsValue() {
-    return state_machine_.AsValue().Pass();
-  }
+  scoped_ptr<base::Value> StateAsValue() const;
 
   bool IsInsideAction(SchedulerStateMachine::Action action) {
     return inside_action_ == action;