Use a direct include of strings headers in chrome/common/, part 1.

chrome/common/extensions/api/extension_action/action_info.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 CHROME_COMMON_EXTENSIONS_API_EXTENSION_ACTION_ACTION_INFO_H_
 #define CHROME_COMMON_EXTENSIONS_API_EXTENSION_ACTION_ACTION_INFO_H_
 
 #include <string>
 
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_icon_set.h"
 #include "googleurl/src/gurl.h"
 
 namespace base {
 class DictionaryValue;
 }
 
 namespace extensions {
 
@@ skipping 55 matching lines @@
   ExtensionIconSet default_icon;
   std::string default_title;
   GURL default_popup_url;
   // action id -- only used with legacy page actions API.
   std::string id;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_API_EXTENSION_ACTION_ACTION_INFO_H_