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.h

 // 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.
 
 #ifndef CONTENT_RENDERER_PLUGIN_CHANNEL_HOST_H_
 #define CONTENT_RENDERER_PLUGIN_CHANNEL_HOST_H_
 
 #include "base/hash_tables.h"
 #include "content/common/np_channel_base.h"
 #include "ipc/ipc_channel_handle.h"
 
+class NPObjectBase;
+
+namespace content {
 class IsListeningFilter;
-class NPObjectBase;
 
 // Encapsulates an IPC channel between the renderer and one plugin process.
 // On the plugin side there's a corresponding PluginChannel.
 class PluginChannelHost : public NPChannelBase {
  public:
 #if defined(OS_MACOSX)
   // TODO(shess): Debugging for http://crbug.com/97285 .  See comment
   // in plugin_channel_host.cc.
   static bool* GetRemoveTrackingFlag();
 #endif
@@ skipping 47 matching lines @@
   // used when the JS debugger is attached in order to avoid browser hangs.
   scoped_refptr<IsListeningFilter> is_listening_filter_;
 
   // True if we are expecting the plugin process to go away - in which case,
   // don't treat it as a crash.
   bool expecting_shutdown_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginChannelHost);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_RENDERER_PLUGIN_CHANNEL_HOST_H_