Update from https://crrev.com/316786

cc/scheduler/delay_based_time_source.h

Index: cc/scheduler/delay_based_time_source.h
diff --git a/cc/scheduler/delay_based_time_source.h b/cc/scheduler/delay_based_time_source.h
index da968a6f017dca57e6e3b20882123e5f13197395..4d7276c97c88fbae31bb72ce0bc93b259c414871 100644
--- a/cc/scheduler/delay_based_time_source.h
+++ b/cc/scheduler/delay_based_time_source.h
@@ -15,14 +15,8 @@ namespace base {
 namespace trace_event {
 class TracedValue;
 }
-
-// TODO(ssid): remove these aliases after the tracing clients are moved to the
-// new trace_event namespace. See crbug.com/451032. ETA: March 2015
-namespace debug {
-using ::base::trace_event::TracedValue;
-}
 class SingleThreadTaskRunner;
-}  // namespace base
+}
 
 namespace cc {
 
@@ -61,7 +55,7 @@ class CC_EXPORT DelayBasedTimeSource
   // Virtual for testing.
   virtual base::TimeTicks Now() const;
 
-  virtual void AsValueInto(base::debug::TracedValue* dict) const;
+  virtual void AsValueInto(base::trace_event::TracedValue* dict) const;
 
  protected:
   DelayBasedTimeSource(base::TimeDelta interval,