Route through a JobService when receiving a message for the GCM Driver

chrome/android/java/src/org/chromium/chrome/browser/JobSchedulerConstants.java

+// Copyright 2017 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.
+
+package org.chromium.chrome.browser;
+
+/**
+ * Constants to use when interacting with the android.app.job.JobScheduler. Primarily, each job
+ * must have a unique ID in order to avoid state of different jobs mixing up.
+ */
+public class JobSchedulerConstants {
+    /**
+     * Job ID for the notification service, which enables us to run a Service Worker in response to
+     * click and close events of notifications.
+     */
+    public static final int NOTIFICATION_SERVICE_JOB_ID = 0;

[nyquist, 2017/02/22 11:38:02]

Are we sure we want to risk using 0 for a unique ID? In case someone assumes
it's a non-good number, etc.?

[Peter Beverloo, 2017/02/23 17:26:55]

Fair enough - updated.

+
+    /**
+     * Job ID for the GCM Driver, which handles received push messages to native consumers such as
+     * Web Push Notifications, execution of which may exceed the permitted time.
+     */
+    public static final int GCM_DRIVER_JOB_ID = 1;
+
+    /** Job ID 2 is reserved for WebView's CrashReceiverService. **/
+}