MD Settings: Remove some ES6 leftovers from CrOS code that break uglify.

chrome/browser/resources/settings/people_page/camera.js

 // 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.
 
 /**
  * @fileoverview
  * 'settings-camera' is the Polymer control used to take a picture from the
  * user webcam to use as a ChromeOS profile picture.
  */
 (function() {
@@ skipping 123 matching lines @@
     this.cameraStartInProgress_ = false;
   },
 
   /**
    * Stops all video tracks associated with a MediaStream object.
    * @param {!MediaStream} stream
    * @private
    */
   stopVideoTracks_: function(stream) {
     var tracks = stream.getVideoTracks();
-    for (var t of tracks)
-      t.stop();
+    for (var i = 0; i < tracks.length; i++)
+      tracks[i].stop();
   },
 
   /**
    * Flip the live camera stream.
    * @private
    */
   onTapFlipPhoto_: function() {
     this.isFlipped_ = !this.isFlipped_;
     this.$.userImageStreamCrop.classList.toggle('flip-x', this.isFlipped_);
 
@@ skipping 44 matching lines @@
     canvas.height = CAPTURE_SIZE.height;
     var ctx = canvas.getContext('2d');
     ctx.translate(CAPTURE_SIZE.width, 0);
     ctx.scale(-1.0, 1.0);
     ctx.drawImage(source, 0, 0);
     return canvas.toDataURL('image/png');
   },
 });
 
 })();