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

chrome/android/java/src/org/chromium/chrome/browser/services/gcm/GCMBackgroundTask.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.services.gcm;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.os.Build;
+import android.os.Bundle;
+import android.support.annotation.MainThread;
+
+import org.chromium.base.Log;
+import org.chromium.components.background_task_scheduler.BackgroundTask;
+import org.chromium.components.background_task_scheduler.TaskParameters;
+import org.chromium.components.gcm_driver.GCMMessage;
+
+/**
+ * Processes jobs that have been scheduled for delivering GCM messages to the native GCM Driver,
+ * processing for which may exceed the lifetime of the GcmListenerService.
+ */
+@TargetApi(Build.VERSION_CODES.N)
+public class GCMBackgroundTask implements BackgroundTask {
+    private static final String TAG = "GCMBackgroundTask";
+
+    /**
+     * Called when a GCM message is ready to be delivered to the GCM Driver consumer. Because we
+     * don't yet know when a message has been fully processed, the task returns that processing has
+     * been completed, and we hope that the system keeps us alive long enough to finish processing.
+     *
+     * @return Boolean indicating whether the WakeLock for this task must be maintained.
+     */
+    @MainThread
+    @Override
+    public boolean onStartTask(
+            Context context, TaskParameters taskParameters, TaskFinishedCallback callback) {
+        Bundle extras = taskParameters.getExtras();
+        if (!GCMMessage.validateBundle(extras)) {
+            Log.e(TAG, "The received bundle containing message data could not be validated.");
+            return false;
+        }
+
+        ChromeGcmListenerService.dispatchMessageToDriver(context, new GCMMessage(extras));
+        return false;
+    }
+
+    /**
+     * Called when the system has determined that processing the GCM message must be stopped.
+     *
+     * @return Boolean indicating whether the task has to be rescheduled.
+     */
+    @MainThread
+    @Override
+    public boolean onStopTask(Context context, TaskParameters taskParameters) {
+        // The GCM Driver has no mechanism for aborting previously dispatched messages.
+        return false;
+    }
+}