Revert 164120 - content/browser: Move more files into the content namespace.

content/browser/trace_controller_impl.h

Index: content/browser/trace_controller_impl.h
===================================================================
--- content/browser/trace_controller_impl.h	(revision 164121)
+++ content/browser/trace_controller_impl.h	(working copy)
@@ -14,9 +14,9 @@
 #include "content/public/browser/trace_controller.h"
 
 class CommandLine;
+class TraceMessageFilter;
 
 namespace content {
-class TraceMessageFilter;
 
 class TraceControllerImpl : public TraceController {
  public:
@@ -56,7 +56,7 @@
   typedef std::set<scoped_refptr<TraceMessageFilter> > FilterMap;
 
   friend struct base::DefaultLazyInstanceTraits<TraceControllerImpl>;
-  friend class TraceMessageFilter;
+  friend class ::TraceMessageFilter;
 
   TraceControllerImpl();
   virtual ~TraceControllerImpl();