Update from https://crrev.com/316786

base/trace_event/trace_event_argument.h

Index: base/trace_event/trace_event_argument.h
diff --git a/base/trace_event/trace_event_argument.h b/base/trace_event/trace_event_argument.h
index 43a0f38ddde518ab78f7508bc3969e6a315e778f..78d37d4122947ce9eecccc7afc016eeafa9aceff 100644
--- a/base/trace_event/trace_event_argument.h
+++ b/base/trace_event/trace_event_argument.h
@@ -56,12 +56,4 @@ class BASE_EXPORT TracedValue : public ConvertableToTraceFormat {
 }  // namespace trace_event
 }  // namespace base
 
-// 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 base {
-namespace debug {
-using base::trace_event::TracedValue;
-}  // namespace debug
-}  // namespace base
-
 #endif  // BASE_TRACE_EVENT_TRACE_EVENT_ARGUMENT_H_