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

cc/quads/draw_quad.h

 // Copyright 2012 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_DRAW_QUAD_H_
 #define CC_QUADS_DRAW_QUAD_H_
 
 #include "base/callback.h"
 #include "cc/base/cc_export.h"
 #include "cc/quads/shared_quad_state.h"
 #include "cc/resources/resource_provider.h"
 
 namespace base {
-namespace trace_event {
+namespace debug {
 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 Value;
 class DictionaryValue;
-}  // namespace base
+}
 
 namespace cc {
 
 // DrawQuad is a bag of data used for drawing a quad. Because different
 // materials need different bits of per-quad data to render, classes that derive
 // from DrawQuad store additional data in their derived instance. The Material
 // enum is used to "safely" downcast to the derived class.
 // Note: quads contain rects and sizes, which live in different spaces. There is
 // the "content space", which is the arbitrary space in which the quad's
 // geometry is defined (generally related to the layer that produced the quad,
@@ skipping 106 matching lines @@
               const gfx::Rect& rect,
               const gfx::Rect& opaque_rect,
               const gfx::Rect& visible_rect,
               bool needs_blending);
   virtual void ExtendValue(base::debug::TracedValue* value) const = 0;
 };
 
 }  // namespace cc
 
 #endif  // CC_QUADS_DRAW_QUAD_H_