Revert of Partial implementation of subscription restrictions.

third_party/WebKit/public/platform/modules/push_messaging/WebPushSubscriptionOptions.h

 // Copyright 2015 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 WebPushSubscriptionOptions_h
 #define WebPushSubscriptionOptions_h
 
-#include "public/platform/WebString.h"
-
 namespace blink {
 
 struct WebPushSubscriptionOptions {
     WebPushSubscriptionOptions()
         : userVisibleOnly(false)
     {
     }
 
     // Indicates that the subscription will only be used for push messages
     // that result in UI visible to the user.
     bool userVisibleOnly;
-
-    // P-256 public key, in uncompressed form, of the app server that can send
-    // push messages to this subscription.
-    WebString applicationServerKey;
 };
 
 } // namespace blink
 
 #endif // WebPushSubscriptionOptions_h