Enables bump scrolling browser test on the Chromoting Waterfall.

remoting/webapp/browser_test/bump_scroll_browser_test.js

 // Copyright 2014 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.
 
 /**
  * @fileoverview
  * @suppress {checkTypes}
  * Browser test for the scenario below:
  * 1. Enter full-screen mode
  * 2. Move the mouse to each edge; verify that the desktop bump-scrolls.
@@ skipping 101 matching lines @@
 
 /**
  * @return {Promise}
  */
 browserTest.Bump_Scroll.prototype.noScrollWindowed = function() {
   var viewport = remoting.desktopConnectedView.getViewportForTesting();
   viewport.setPluginSizeForBumpScrollTesting(
       window.innerWidth + this.kHostDesktopSizeDelta,
       window.innerHeight + this.kHostDesktopSizeDelta);
   this.moveMouseTo(0, 0);
-  return this.verifyScroll(undefined, undefined);
+  return this.verifyNoScroll();
 };
 
 /**
  * @return {Promise}
  */
 browserTest.Bump_Scroll.prototype.noScrollSmaller = function() {
   var viewport = remoting.desktopConnectedView.getViewportForTesting();
   viewport.setPluginSizeForBumpScrollTesting(
       window.innerWidth - this.kHostDesktopSizeDelta,
       window.innerHeight - this.kHostDesktopSizeDelta);
   this.moveMouseTo(0, 0);
-  return this.verifyScroll(undefined, undefined);
+  return this.verifyNoScroll();
 };
 
 /**
  * @param {number} widthFraction
  * @param {number} heightFraction
  * @return {Promise}
  */
 browserTest.Bump_Scroll.prototype.scrollDirection =
     function(widthFraction, heightFraction) {
   var viewport = remoting.desktopConnectedView.getViewportForTesting();
@@ skipping 65 matching lines @@
  * verifyScroll() is complicated enough to warrant a test.
  * @return {Promise}
  */
 browserTest.Bump_Scroll.prototype.testVerifyScroll = function() {
   var STARTED = remoting.BumpScroller.Events.bumpScrollStarted;
   var STOPPED = remoting.BumpScroller.Events.bumpScrollStopped;
   var fakeViewport = new browserTest.FakeDesktopViewport;
   var that = this;
 
   // No events raised (e.g. windowed mode).
-  var result = this.verifyScroll(undefined, undefined, fakeViewport)
+  var result = this.verifyNoScroll(fakeViewport)
 
   .then(function() {
     // Start and end events raised, but no scrolling (e.g. full-screen mode
     // with host desktop <= window size).
     fakeViewport = new browserTest.FakeDesktopViewport;
-    var result = that.verifyScroll(undefined, undefined, fakeViewport);
+    var result = that.verifyNoScroll(fakeViewport);
     fakeViewport.raiseEvent(STARTED, {});
     fakeViewport.raiseEvent(STOPPED, {});
     return result;
 
   }).then(function() {
     // Start and end events raised, with incorrect scrolling.
     fakeViewport = new browserTest.FakeDesktopViewport;
     var result = base.Promise.negate(
         that.verifyScroll(2, 2, fakeViewport));
     fakeViewport.raiseEvent(STARTED, {});
@@ skipping 76 matching lines @@
     if (expectedTop === undefined && expectedLeft === undefined) {
       return Promise.resolve();
     } else {
       return Promise.reject(
           new Error('Scroll expected but no start event fired.'));
     }
   }).then(function() {
     return verifyPluginPosition();
   });
 };
+
+/**
+ * @param {browserTest.FakeDesktopViewport=} opt_desktopViewport
+ *     DesktopViewport fake, for testing.
+ *
+ * @return {Promise<boolean>} A promise that resolves to true if no scrolling
+ *   occurs within a timeout.
+ */
+browserTest.Bump_Scroll.prototype.verifyNoScroll =
+    function(opt_desktopViewport) {
+  var desktopViewport = opt_desktopViewport ||
+                        remoting.desktopConnectedView.getViewportForTesting();
+  var bumpScroller = desktopViewport.getBumpScrollerForTesting();
+  if (!bumpScroller) {
+    Promise.resolve(true);
+  }
+  return this.verifyScroll(undefined, undefined, desktopViewport);
+};