Use a direct include of strings headers in remoting/.

remoting/host/disconnect_window_mac.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.
 
 #import <Cocoa/Cocoa.h>
 
 #include <string>
 
 #include "base/callback.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 
 namespace remoting {
 struct UiStrings;
 }
 
 // Controller for the disconnect window which allows the host user to
 // quickly disconnect a session.
 @interface DisconnectWindowController : NSWindowController {
  @private
@@ skipping 13 matching lines @@
 // A floating window with a custom border. The custom border and background
 // content is defined by DisconnectView. Declared here so that it can be
 // instantiated via a xib.
 @interface DisconnectWindow : NSWindow
 @end
 
 // The custom background/border for the DisconnectWindow. Declared here so that
 // it can be instantiated via a xib.
 @interface DisconnectView : NSView
 @end