Push API: Don't require notification if tab is visible.

content/public/browser/push_messaging_service.h

 // Copyright 2014 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_PUSH_MESSAGING_SERVICE_H_
 #define CONTENT_PUBLIC_BROWSER_PUSH_MESSAGING_SERVICE_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "content/common/content_export.h"
 #include "content/public/common/push_messaging_status.h"
 #include "third_party/WebKit/public/platform/WebPushPermissionStatus.h"
 #include "url/gurl.h"
 
 namespace content {
 
+class WebContents;
+
 // A push service-agnostic interface that the Push API uses for talking to
 // push messaging services like GCM. Must only be used on the UI thread.
 class CONTENT_EXPORT PushMessagingService {
  public:
   using RegisterCallback =
       base::Callback<void(const std::string& /* registration_id */,
                           PushRegistrationStatus /* status */)>;
   using UnregisterCallback = base::Callback<void(PushUnregistrationStatus)>;
 
   virtual ~PushMessagingService() {}
@@ skipping 27 matching lines @@
   virtual void Unregister(const GURL& requesting_origin,
                           int64 service_worker_registration_id,
                           const UnregisterCallback& callback) = 0;
 
   // Checks the permission status for the requesting origin. Permission is only
   // ever granted when the requesting origin matches the top level embedding
   // origin.
   virtual blink::WebPushPermissionStatus GetPermissionStatus(
       const GURL& requesting_origin,
       const GURL& embedding_origin) = 0;
+
+ protected:
+  bool IsWebContentsUserVisible(const WebContents* web_contents);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_PUSH_MESSAGING_SERVICE_H_