Move a bunch of code in content\renderer to the content namespace.

content/renderer/devtools_agent_filter.h

Index: content/renderer/devtools_agent_filter.h
===================================================================
--- content/renderer/devtools_agent_filter.h	(revision 163045)
+++ content/renderer/devtools_agent_filter.h	(working copy)
@@ -12,6 +12,8 @@
 class MessageLoop;
 struct DevToolsMessageData;
 
+namespace content {
+
 // DevToolsAgentFilter is registered as an IPC filter in order to be able to
 // dispatch messages while on the IO thread. The reason for that is that while
 // debugging, Render thread is being held by the v8 and hence no messages
@@ -41,4 +43,6 @@
   DISALLOW_COPY_AND_ASSIGN(DevToolsAgentFilter);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_RENDERER_DEVTOOLS_AGENT_FILTER_H_