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

content/renderer/plugin_channel_host.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/plugin_channel_host.h"
 
 #include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "content/common/child_process.h"
 #include "content/common/npobject_base.h"
@@ skipping 30 matching lines @@
 
 // GetRemoveTrackingFlag() exposes this so that
 // WebPluginDelegateProxy::Initialize() can do scoped set/reset.  When
 // true, RemoveRoute() knows WBDP::Initialize() is on the stack, and
 // records the backtrace.
 bool remove_tracking = false;
 
 }  // namespace
 #endif
 
+namespace content {
+
 // A simple MessageFilter that will ignore all messages and respond to sync
 // messages with an error when is_listening_ is false.
 class IsListeningFilter : public IPC::ChannelProxy::MessageFilter {
  public:
   IsListeningFilter() : channel_(NULL) {}
 
   // MessageFilter overrides
   virtual void OnFilterRemoved() {}
   virtual void OnFilterAdded(IPC::Channel* channel) { channel_ = channel;  }
   virtual bool OnMessageReceived(const IPC::Message& message);
@@ skipping 158 matching lines @@
 
   NPChannelBase::OnChannelError();
 
   for (ProxyMap::iterator iter = proxies_.begin();
        iter != proxies_.end(); iter++) {
     iter->second->OnChannelError();
   }
 
   proxies_.clear();
 }
+
+}  // namespace content