Move a bunch of code in content\common (as well as a few left in renderer) to the content namespace.

content/common/gpu/gpu_watchdog.h

 // Copyright (c) 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 CONTENT_COMMON_GPU_GPU_WATCHDOG_H_
 #define CONTENT_COMMON_GPU_GPU_WATCHDOG_H_
 
+namespace content {
+
 // Interface for objects that monitor the a GPUProcessor's progress. The
 // GPUProcessor will regularly invoke CheckArmed.
 class GpuWatchdog {
  public:
   virtual void CheckArmed() = 0;
 
  protected:
   GpuWatchdog() {}
   virtual ~GpuWatchdog() {};
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GpuWatchdog);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_COMMON_GPU_GPU_WATCHDOG_H_