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

content/common/gpu/texture_image_transport_surface.h

Index: content/common/gpu/texture_image_transport_surface.h
===================================================================
--- content/common/gpu/texture_image_transport_surface.h	(revision 163290)
+++ content/common/gpu/texture_image_transport_surface.h	(working copy)
@@ -12,6 +12,7 @@
 #include "gpu/command_buffer/service/texture_manager.h"
 #include "ui/gl/gl_surface.h"
 
+namespace content {
 class GpuChannelManager;
 
 class TextureImageTransportSurface :
@@ -124,4 +125,6 @@
   DISALLOW_COPY_AND_ASSIGN(TextureImageTransportSurface);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_COMMON_GPU_TEXTURE_IMAGE_TRANSPORT_SURFACE_H_