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

ppapi/proxy/ppapi_command_buffer_proxy.h

Index: ppapi/proxy/ppapi_command_buffer_proxy.h
===================================================================
--- ppapi/proxy/ppapi_command_buffer_proxy.h	(revision 163290)
+++ ppapi/proxy/ppapi_command_buffer_proxy.h	(working copy)
@@ -40,8 +40,8 @@
   virtual bool SignalSyncPoint(uint32 sync_point,
                                const base::Closure& callback) OVERRIDE;
   virtual void SetMemoryAllocationChangedCallback(
-      const base::Callback<void(const GpuMemoryAllocationForRenderer&)>&
-          callback) OVERRIDE;
+      const base::Callback<void(
+        const content::GpuMemoryAllocationForRenderer&)>& callback) OVERRIDE;
   virtual bool SetParent(CommandBufferProxy* parent_command_buffer,
                          uint32 parent_texture_id) OVERRIDE;
   virtual void SetChannelErrorCallback(const base::Closure& callback) OVERRIDE;