Update from https://crrev.com/316786

base/trace_event/trace_event_argument.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_TRACE_EVENT_TRACE_EVENT_ARGUMENT_H_
 #define BASE_TRACE_EVENT_TRACE_EVENT_ARGUMENT_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 38 matching lines @@
   ListValue* GetCurrentArray();
 
   scoped_ptr<base::Value> root_;
   std::vector<Value*> stack_;
   DISALLOW_COPY_AND_ASSIGN(TracedValue);
 };
 
 }  // 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_