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

content/common/gpu/gpu_command_buffer_stub.h

Index: content/common/gpu/gpu_command_buffer_stub.h
===================================================================
--- content/common/gpu/gpu_command_buffer_stub.h	(revision 163290)
+++ content/common/gpu/gpu_command_buffer_stub.h	(working copy)
@@ -33,11 +33,6 @@
 #include "ui/surface/accelerated_surface_mac.h"
 #endif
 
-class GpuChannel;
-struct GpuMemoryAllocation;
-class GpuVideoDecodeAccelerator;
-class GpuWatchdog;
-
 namespace gpu {
 namespace gles2 {
 class ImageManager;
@@ -45,6 +40,13 @@
 }
 }
 
+namespace content {
+
+class GpuChannel;
+class GpuVideoDecodeAccelerator;
+class GpuWatchdog;
+struct GpuMemoryAllocation;
+
 // This Base class is used to expose methods of GpuCommandBufferStub used for
 // testability.
 class CONTENT_EXPORT GpuCommandBufferStubBase {
@@ -298,4 +300,6 @@
   DISALLOW_COPY_AND_ASSIGN(GpuCommandBufferStub);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_COMMON_GPU_GPU_COMMAND_BUFFER_STUB_H_