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

content/public/browser/push_messaging_service.cc

+// 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.
+
+#include "content/public/browser/push_messaging_service.h"
+
+#include "content/browser/web_contents/web_contents_impl.h"
+#include "content/public/browser/web_contents.h"
+
+namespace content {
+
+bool PushMessagingService::IsWebContentsUserVisible(
+    const WebContents* web_contents) {
+  const WebContentsImpl* web_contents_impl =
+      static_cast<const WebContentsImpl*>(web_contents);
+  return web_contents_impl->should_normally_be_visible();
+}
+
+}  // namespace content