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

cc/resources/one_copy_tile_task_worker_pool.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 CC_RESOURCES_ONE_COPY_TILE_TASK_WORKER_POOL_H_
 #define CC_RESOURCES_ONE_COPY_TILE_TASK_WORKER_POOL_H_
 
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/values.h"
 #include "cc/base/scoped_ptr_deque.h"
 #include "cc/output/context_provider.h"
 #include "cc/resources/resource_provider.h"
 #include "cc/resources/tile_task_runner.h"
 #include "cc/resources/tile_task_worker_pool.h"
 
 namespace base {
-namespace debug {
+namespace trace_event {
 class ConvertableToTraceFormat;
 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::ConvertableToTraceFormat;
+using ::base::trace_event::TracedValue;
 }
+}  // namespace base
 
 namespace cc {
 class ResourcePool;
 class ScopedResource;
 
 typedef int64 CopySequenceNumber;
 
 class CC_EXPORT OneCopyTileTaskWorkerPool : public TileTaskWorkerPool,
                                             public TileTaskRunner,
                                             public TileTaskClient {
@@ skipping 100 matching lines @@
   // canceled when ScheduleTasks() is called.
   base::WeakPtrFactory<OneCopyTileTaskWorkerPool>
       task_set_finished_weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OneCopyTileTaskWorkerPool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_ONE_COPY_TILE_TASK_WORKER_POOL_H_