Move a bunch more code into the content namespace.

content/common/edit_command.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_COMMON_EDIT_COMMAND_H_
 #define CONTENT_COMMON_EDIT_COMMAND_H_
 
 #include <string>
 #include <vector>
 
+namespace content {
+
 // Types related to sending edit commands to the renderer.
 struct EditCommand {
   EditCommand() { }
   EditCommand(const std::string& n, const std::string& v)
       : name(n), value(v) {
   }
 
   std::string name;
   std::string value;
 };
 
 typedef std::vector<EditCommand> EditCommands;
 
+}  // namespace content
+
 #endif  // CONTENT_COMMON_EDIT_COMMAND_H_