PDF Plugin: Add compile targets for a few files.

chrome/browser/resources/pdf/gesture_detector.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.
 
 'use strict';
 
 /**
  * A class that listens for touch events and produces events when these
  * touches form gestures (e.g. pinching).
  */
 class GestureDetector {
   /**
    * Constructs a GestureDetector.
    * @param {!Element} element The element to monitor for touch gestures.
    */
   constructor(element) {
+    /** @private {!Element} */
     this.element_ = element;
 
     this.element_.addEventListener(
-        'touchstart', this.onTouchStart_.bind(this), { passive: true });
+        'touchstart',
+        /** @type {function(!Event)} */ (this.onTouchStart_.bind(this)),

[dpapad, 2017/05/23 18:38:38]

Changed the code to use a different function reference for each of the three
listeners (as it was doing before), since the testPreventNativePinchZoom started
failing.

I don't understand why it is important to pass 3 different (but identical)
functions to touchmove, touchend and touchcancel, it seems more of a test
problem (state leaking across listeners), than a real issue in the prod code.

+        { passive: true });
+
     this.element_.addEventListener(
-        'touchmove', this.onTouch_.bind(this), { passive: false });
+        'touchmove',
+        /** @type {function(!Event)} */ (this.onTouch_.bind(this)),
+        { passive: false });
     this.element_.addEventListener(
-        'touchend', this.onTouch_.bind(this), { passive: true });
+        'touchend',
+        /** @type {function(!Event)} */ (this.onTouch_.bind(this)),
+        { passive: true });
     this.element_.addEventListener(
-        'touchcancel', this.onTouch_.bind(this), { passive: true });
+        'touchcancel',
+        /** @type {function(!Event)} */ (this.onTouch_.bind(this)),
+        { passive: true });
 
     this.pinchStartEvent_ = null;
     this.lastTouchTouchesCount_ = 0;
+
+    /** @private {?TouchEvent} */
     this.lastEvent_ = null;
 
+    /** @private {!Map<string, !Array<!Function>>} */
     this.listeners_ = new Map([
       ['pinchstart', []],
       ['pinchupdate', []],
       ['pinchend', []]
     ]);
   }
 
   /**
    * Add a |listener| to be notified of |type| events.
    * @param {string} type The event type to be notified for.
-   * @param {Function} listener The callback.
+   * @param {!Function} listener The callback.
    */
   addEventListener(type, listener) {
     if (this.listeners_.has(type)) {
       this.listeners_.get(type).push(listener);
     }
   }
 
   /**
    * Returns true if the last touch start was a two finger touch.
    * @return {boolean} True if the last touch start was a two finger touch.
@@ skipping 34 matching lines @@
 
   /**
    * The callback for touch move, end, and cancel events on the element.
    * @private
    * @param {!TouchEvent} event Touch event on the element.
    */
   onTouch_(event) {
     if (!this.pinchStartEvent_)
       return;
 
+    let lastEvent = /** @type {!TouchEvent} */ (this.lastEvent_);
+
     // Check if the pinch ends with the current event.
     if (event.touches.length < 2 ||
-        this.lastEvent_.touches.length !== event.touches.length) {
+        lastEvent.touches.length !== event.touches.length) {
       let startScaleRatio = GestureDetector.pinchScaleRatio_(
-          this.lastEvent_, this.pinchStartEvent_);
-      let center = GestureDetector.center_(this.lastEvent_);
+          lastEvent, this.pinchStartEvent_);
+      let center = GestureDetector.center_(lastEvent);
       let endEvent = {
         type: 'pinchend',
         startScaleRatio: startScaleRatio,
         center: center
       };
       this.pinchStartEvent_ = null;
       this.lastEvent_ = null;
       this.notify_(endEvent);
       return;
     }
 
     // We must preventDefault two finger touchmoves. By doing so native
     // pinch-zoom does not interfere with our way of handling the event.
     event.preventDefault();
 
-    let scaleRatio = GestureDetector.pinchScaleRatio_(event, this.lastEvent_);
+    let scaleRatio = GestureDetector.pinchScaleRatio_(event, lastEvent);
     let startScaleRatio = GestureDetector.pinchScaleRatio_(
         event, this.pinchStartEvent_);
     let center = GestureDetector.center_(event);
     this.notify_({
       type: 'pinchupdate',
       scaleRatio: scaleRatio,
       direction: scaleRatio > 1.0 ? 'in' : 'out',
       startScaleRatio: startScaleRatio,
       center: center
     });
@@ skipping 38 matching lines @@
    */
   static center_(event) {
     let touch1 = event.touches[0];
     let touch2 = event.touches[1];
     return {
       x: (touch1.clientX + touch2.clientX) / 2,
       y: (touch1.clientY + touch2.clientY) / 2
     };
   }
 };