Add unit tests for the Background Scheduler.

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

 // Copyright 2016 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;
 
 import android.content.Context;
 import android.os.Bundle;
 
 import com.google.android.gms.gcm.GcmNetworkManager;
 import com.google.android.gms.gcm.GcmTaskService;
 import com.google.android.gms.gcm.TaskParams;
 
 import org.chromium.base.Log;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.base.library_loader.ProcessInitException;
 import org.chromium.chrome.browser.init.ChromeBrowserInitializer;
 import org.chromium.chrome.browser.ntp.snippets.SnippetsBridge;
 import org.chromium.chrome.browser.ntp.snippets.SnippetsLauncher;
 import org.chromium.chrome.browser.offlinepages.BackgroundOfflinerTask;
 import org.chromium.chrome.browser.offlinepages.OfflinePageUtils;
+import org.chromium.chrome.browser.offlinepages.SchedulerBridge;
 import org.chromium.chrome.browser.precache.PrecacheController;
 
 /**
  * {@link ChromeBackgroundService} is scheduled through the {@link GcmNetworkManager} when the
  * browser needs to be launched for scheduled tasks, or in response to changing network or power
  * conditions.
  */
 public class ChromeBackgroundService extends GcmTaskService {
     private static final String TAG = "BackgroundService";
 
@@ skipping 84 matching lines @@
     @VisibleForTesting
     protected boolean hasPrecacheInstance() {
         return PrecacheController.hasInstance();
     }
 
     @VisibleForTesting
     protected void precache(Context context, String tag) {
         PrecacheController.get(context).precache(tag);
     }
 
+    @VisibleForTesting

[dougarnett, 2016/06/02 00:14:45]

? but the following method is private so confused by this annotation

[Pete Williamson, 2016/06/02 00:42:06]

I meant to mark it as testable since the test now calls it.  Not sure why it
compiled, but I changed it to protected like the others.

     private void handleOfflinePageBackgroundLoad(Context context, Bundle bundle) {
         if (!hasPrecacheInstance()) {
             launchBrowser(context);
         }
 
         // Call BackgroundTask, provide context.
-        BackgroundOfflinerTask.startBackgroundRequests(context, bundle);
+        BackgroundOfflinerTask task = new BackgroundOfflinerTask(new SchedulerBridge());
+        task.startBackgroundRequests(context, bundle);
         // TODO(petewil) if processBackgroundRequest returns false, return RESTART_RESCHEDULE
         // to the GcmNetworkManager
     }
 
     @VisibleForTesting
     @SuppressFBWarnings("DM_EXIT")
     protected void launchBrowser(Context context) {
         Log.i(TAG, "Launching browser");
         try {
             ChromeBrowserInitializer.getInstance(this).handleSynchronousStartup();
         } catch (ProcessInitException e) {
             Log.e(TAG, "ProcessInitException while starting the browser process");
             // Since the library failed to initialize nothing in the application
             // can work, so kill the whole application not just the activity.
             System.exit(-1);
         }
     }
 
     @Override
     public void onInitializeTasks() {
         BackgroundSyncLauncher.rescheduleTasksOnUpgrade(this);
         PrecacheController.rescheduleTasksOnUpgrade(this);
     }
 }