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

content/browser/gpu/gpu_process_host.cc

Index: content/browser/gpu/gpu_process_host.cc
===================================================================
--- content/browser/gpu/gpu_process_host.cc	(revision 163290)
+++ content/browser/gpu/gpu_process_host.cc	(working copy)
@@ -48,6 +48,8 @@
 
 using content::BrowserThread;
 using content::ChildProcessHost;
+using content::GpuChildThread;
+using content::GpuProcess;
 using content::RenderProcessHost;
 using content::RenderWidgetHelper;
 using content::RenderWidgetHost;