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

content/renderer/render_process_impl.h

Index: content/renderer/render_process_impl.h
===================================================================
--- content/renderer/render_process_impl.h	(revision 163290)
+++ content/renderer/render_process_impl.h	(working copy)
@@ -12,6 +12,8 @@
 class PlatformCanvas;
 }
 
+namespace content {
+
 // Implementation of the RenderProcess interface for the regular browser.
 // See also MockRenderProcess which implements the active "RenderProcess" when
 // running under certain unit tests.
@@ -74,4 +76,6 @@
   DISALLOW_COPY_AND_ASSIGN(RenderProcessImpl);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_RENDERER_RENDER_PROCESS_IMPL_H_