Use a direct include of strings headers in content/p*/.

content/public/browser/web_ui.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_PUBLIC_BROWSER_WEB_UI_H_
 #define CONTENT_PUBLIC_BROWSER_WEB_UI_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "content/common/content_export.h"
 #include "content/public/common/page_transition_types.h"
 #include "ui/base/layout.h"
 
 class GURL;
 
 namespace base {
 class ListValue;
 class Value;
 }
@@ skipping 91 matching lines @@
                                       const base::Value& arg3,
                                       const base::Value& arg4) = 0;
   virtual void CallJavascriptFunction(
       const std::string& function_name,
       const std::vector<const base::Value*>& args) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_WEB_UI_H_