Move the remaning files in content\common to the content namespace.

content/common/npobject_proxy.cc

 // Copyright (c) 2011 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/common/npobject_proxy.h"
 
 #include "content/common/np_channel_base.h"
 #include "content/common/npobject_util.h"
 #include "content/common/plugin_messages.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebBindings.h"
 #include "webkit/glue/webkit_glue.h"
 #include "webkit/plugins/npapi/plugin_instance.h"
 #include "webkit/plugins/npapi/plugin_host.h"
 
 using WebKit::WebBindings;
 
+namespace content {
+
 struct NPObjectWrapper {
     NPObject object;
     NPObjectProxy* proxy;
 };
 
 NPClass NPObjectProxy::npclass_proxy_ = {
   NP_CLASS_STRUCT_VERSION,
   NPObjectProxy::NPAllocate,
   NPObjectProxy::NPDeallocate,
   NPObjectProxy::NPPInvalidate,
@@ skipping 462 matching lines @@
   proxy->Send(msg);
   // Send may delete proxy.
   proxy = NULL;
   if (!result)
     return false;
 
   CreateNPVariant(
       result_param, channel.get(), result_var, containing_window, page_url);
   return true;
 }
+
+}  // namespace content