Handle long press in PDF documents.

chrome/test/data/pdf/gesture_detector_test.js

 // 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.
 
 chrome.test.runTests(function() {
   'use strict';
 
   class StubElement {
     constructor() {
       this.listeners = new Map([
@@ skipping 194 matching lines @@
 
       let pinchUpdateEvent = new MockTouchEvent('touchmove', [
         {clientX: 0, clientY: 0},
         {clientX: 0, clientY: 4}
       ]);
       stubElement.sendEvent(pinchUpdateEvent);
       chrome.test.assertEq('pinchupdate', pinchListener.lastEvent.type);
       chrome.test.assertTrue(pinchUpdateEvent.defaultPrevented);
 
       chrome.test.succeed();
+    },
+
+    function testWasTwoFingerTouch() {
+      let stubElement = new StubElement();
+      let gestureDetector = new GestureDetector(stubElement);
+
+
+      chrome.test.assertFalse(gestureDetector.wasTwoFingerTouch(),
+          "Should not have two finger touch before first touch event.");
+
+      stubElement.sendEvent(new MockTouchEvent('touchstart', []));

[Kevin McNee, 2017/05/04 15:38:55]

nit: AFAIK I don't think it's possible to have a touchstart with no touches. I'd
do a 1 finger touchstart here, especially since a 1 finger touchstart followed
by a 2 finger touchstart is what you would see with an actual 2 finger tap.

[dsinclair, 2017/05/04 17:55:54]

Done.

+      chrome.test.assertFalse(gestureDetector.wasTwoFingerTouch(),
+          "Should not have a two finger touch with no touches.");
+
+      stubElement.sendEvent(new MockTouchEvent('touchstart', [
+          {clientX: 0, clientY: 0},
+          {clientX: 2, clientY: 2}]));

[Kevin McNee, 2017/05/04 15:38:55]

nit: style. Let's be consistent in this file and use block formatting for all of
these touch arrays.

2 space indent, line break before "]"
https://google.github.io/styleguide/jsguide.html#formatting-array-literals

[dsinclair, 2017/05/04 17:55:54]

Done.

+      chrome.test.assertTrue(gestureDetector.wasTwoFingerTouch(),
+          "Should have a two finger touch.");;

[Kevin McNee, 2017/05/04 15:38:55]

nit: double semicolon

[dsinclair, 2017/05/04 17:55:54]

Done.

+
+      // Make sure we keep |wasTwoFingerTouch| true after the end event.
+      stubElement.sendEvent(new MockTouchEvent('touchend', []));
+      chrome.test.assertTrue(gestureDetector.wasTwoFingerTouch(),
+          "Should maintain two finger touch after touchend.");
+
+      stubElement.sendEvent(new MockTouchEvent('touchstart', [
+          {clientX: 0, clientY: 0},
+          {clientX: 2, clientY: 2},
+          {clientX: 4, clientY: 4}]));
+      chrome.test.assertFalse(gestureDetector.wasTwoFingerTouch(),
+          "Should not have two finger touch with 3 touches.");
+
+      chrome.test.succeed();
     }
   ];
 }());