Move remaining content test code into the content namespace.

content/public/test/mock_render_thread.cc

Index: content/public/test/mock_render_thread.cc
===================================================================
--- content/public/test/mock_render_thread.cc	(revision 164732)
+++ content/public/test/mock_render_thread.cc	(working copy)
@@ -119,15 +119,15 @@
     IPC::ChannelProxy::OutgoingMessageFilter* filter) {
 }
 
-void MockRenderThread::AddObserver(content::RenderProcessObserver* observer) {
+void MockRenderThread::AddObserver(RenderProcessObserver* observer) {
 }
 
 void MockRenderThread::RemoveObserver(
-    content::RenderProcessObserver* observer) {
+    RenderProcessObserver* observer) {
 }
 
 void MockRenderThread::SetResourceDispatcherDelegate(
-    content::ResourceDispatcherDelegate* delegate) {
+    ResourceDispatcherDelegate* delegate) {
 }
 
 void MockRenderThread::WidgetHidden() {