Revert of Move tracing namespace from base::debug to base::trace_event.

cc/quads/render_pass.h

 // Copyright 2011 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 CC_QUADS_RENDER_PASS_H_
 #define CC_QUADS_RENDER_PASS_H_
 
 #include <utility>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/containers/hash_tables.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/scoped_ptr_vector.h"
 #include "cc/quads/list_container.h"
 #include "cc/quads/render_pass_id.h"
 #include "skia/ext/refptr.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/rect_f.h"
 #include "ui/gfx/transform.h"
 
 namespace base {
-namespace trace_event {
+namespace debug {
 class TracedValue;
 }
 class Value;
-
-// 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;
-}
-}  // namespace base
+};
 
 namespace cc {
 
 class DrawQuad;
 class CopyOutputRequest;
 class RenderPassDrawQuad;
 class SharedQuadState;
 
 // A list of DrawQuad objects, sorted internally in front-to-back order.
 class QuadList : public ListContainer<DrawQuad> {
@@ skipping 102 matching lines @@
   }
 };
 }  // namespace BASE_HASH_NAMESPACE
 
 namespace cc {
 typedef ScopedPtrVector<RenderPass> RenderPassList;
 typedef base::hash_map<RenderPassId, RenderPass*> RenderPassIdHashMap;
 }  // namespace cc
 
 #endif  // CC_QUADS_RENDER_PASS_H_