remove unnecessary thread hopping when updating Download notifications

chrome/android/javatests/src/org/chromium/chrome/browser/download/SystemDownloadNotifierTest.java

 // 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.
 
 package org.chromium.chrome.browser.download;
 
 import android.content.Context;
 import android.support.test.filters.SmallTest;
 import android.test.InstrumentationTestCase;
 
@@ skipping 28 matching lines @@
         @Override
         void stopService() {
             mStarted = false;
         }
 
         @Override
         void onSuccessNotificationShown(
                 final SystemDownloadNotifier.PendingNotificationInfo notificationInfo,
                 final int notificationId) {
         }
+
+        @Override
+        void updateDownloadNotification(final PendingNotificationInfo notificationInfo) {
+            ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+                @Override
+                public void run() {
+                    MockSystemDownloadNotifier.super.updateDownloadNotification(notificationInfo);
+                }
+            });
+        }
     }
 
     @Override
     public void setUp() throws Exception {
         super.setUp();
         mDownloadNotifier = new MockSystemDownloadNotifier(getInstrumentation().getTargetContext());
     }
 
     /**
      * Helper method to simulate that the DownloadNotificationService is connected.
@@ skipping 56 matching lines @@
         mDownloadNotifier.notifyDownloadFailed(info);
         mDownloadNotifier.notifyDownloadSuccessful(info2, 100L, true, false);
         CriteriaHelper.pollUiThread(new Criteria() {
             @Override
             public boolean isSatisfied() {
                 return !mDownloadNotifier.mStarted;
             }
         });
     }
 }