Use a direct include of strings headers in ipc/, jingle/, media/.

jingle/notifier/listener/notification_defines.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 "jingle/notifier/listener/notification_defines.h"
 
 #include <cstddef>
 
 #include "base/json/string_escape.h"
 #include "base/logging.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "base/values.h"
 
 namespace notifier {
 
 Subscription::Subscription() {}
 Subscription::~Subscription() {}
 
 bool Subscription::Equals(const Subscription& other) const {
   return channel == other.channel && from == other.from;
 }
@@ skipping 45 matching lines @@
 std::string Notification::ToString() const {
   // |channel| or |data| could hold binary data, so use GetDoubleQuotedJson()
   // to escape them.
   const std::string& printable_channel = base::GetDoubleQuotedJson(channel);
   const std::string& printable_data = base::GetDoubleQuotedJson(data);
   return
       "{ channel: " + printable_channel + ", data: " + printable_data + " }";
 }
 
 }  // namespace notifier