Move a bunch of content\common code into the content namespace.

content/common/gpu/gpu_surface_lookup.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_SURFACE_LOOKUP_H_
 #define CONTENT_COMMON_GPU_GPU_SURFACE_LOOKUP_H_
 
 #include "ui/gfx/native_widget_types.h"
 
+namespace content {
+
 // This class provides an interface to look up window surface handles
 // that cannot be sent through the IPC channel.
 class GpuSurfaceLookup {
  public:
   GpuSurfaceLookup() { }
   virtual ~GpuSurfaceLookup() { }
 
   static GpuSurfaceLookup* GetInstance();
   static void InitInstance(GpuSurfaceLookup* lookup);
 
   virtual gfx::AcceleratedWidget GetNativeWidget(int surface_id) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GpuSurfaceLookup);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_COMMON_GPU_GPU_SURFACE_LOOKUP_H_