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

content/common/net/url_request_user_data.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/common/net/url_request_user_data.h"
 
+namespace content {
+
 URLRequestUserData::URLRequestUserData(int render_process_id,
                                        int render_view_id)
     : render_process_id_(render_process_id),
       render_view_id_(render_view_id) {}
 
 URLRequestUserData::~URLRequestUserData() {}
 
 // static
 const void* URLRequestUserData::kUserDataKey =
     static_cast<const void*>(&URLRequestUserData::kUserDataKey);
+
+}  // namespace content