Fix DownloadNotificationService foreground state

chrome/android/javatests/src/org/chromium/chrome/browser/download/MockDownloadNotificationService.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.app.Notification;
 import android.content.Context;
 
 import org.chromium.base.ThreadUtils;
@@ skipping 21 matching lines @@
     @Override
     public void startForeground() {}
 
     @Override
     public void cancelOffTheRecordDownloads() {
         super.cancelOffTheRecordDownloads();
         mPaused = true;
     }
 
     @Override
+    boolean hasDownloadNotifications(Integer notificationIdToIgnore) {
+        // Cancelling notifications here is synchronous, so we don't really have to worry about
+        // {@code notificationIdToIgnore}, but address it properly anyway.
+        if (mNotificationIds.size() == 1 && notificationIdToIgnore != null) {
+            return !mNotificationIds.contains(notificationIdToIgnore);
+        }
+
+        return !mNotificationIds.isEmpty();
+    }
+
+    @Override
+    void cancelSummaryNotification() {}
+
+    @Override
     void updateNotification(int id, Notification notification) {
         if (!mNotificationIds.contains(id)) {
             mNotificationIds.add(id);
             mLastNotificationId = id;
         }
     }
 
     public boolean isPaused() {
         return mPaused;
     }
@@ skipping 62 matching lines @@
     public void notifyDownloadCanceled(final String downloadGuid) {
         ThreadUtils.runOnUiThreadBlocking(new Runnable() {
             @Override
             public void run() {
                 MockDownloadNotificationService.super.notifyDownloadCanceled(downloadGuid);
             }
         });
     }
 }