[cros] Avatar picker: various fixes for web camera problems.

chrome/browser/resources/chromeos/user_images_grid.js

 // Copyright (c) 2012 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.
 
 cr.define('options', function() {
   /** @const */ var ArrayDataModel = cr.ui.ArrayDataModel;
   /** @const */ var Grid = cr.ui.Grid;
   /** @const */ var GridItem = cr.ui.GridItem;
   /** @const */ var GridSelectionController = cr.ui.GridSelectionController;
   /** @const */ var ListSingleSelectionModel = cr.ui.ListSingleSelectionModel;
 
   /**
    * Interval between consecutive camera presence checks in msec while camera is
    * not present.
    * @const
    */
   var CAMERA_CHECK_INTERVAL_MS = 3000;
 
   /**
    * Interval between consecutive camera liveness checks in msec.
    * @const
    */
-  var CAMERA_LIVENESS_CHECK_MS = 1000;
+  var CAMERA_LIVENESS_CHECK_MS = 3000;
 
   /**
    * Number of frames recorded by takeVideo().
    * @const
    */
   var RECORD_FRAMES = 48;
 
   /**
    * FPS at which camera stream is recorded.
    * @const
@@ skipping 129 matching lines @@
 
     /**
      * Handles selection change.
      * @param {Event} e Double click Event.
      * @private
      */
     handleChange_: function(e) {
       if (this.selectedItem === null)
         return;
 
+      var oldSelectionType = this.selectionType;
+
       // Update current selection type.
       this.selectionType = this.selectedItem.type;
 
       // Show grey silhouette with the same border as stock images.
       if (/^chrome:\/\/theme\//.test(this.selectedItemUrl))
         this.previewElement.classList.add('default-image');
 
       this.updatePreview_();
 
-      cr.dispatchSimpleEvent(this, 'select');
+      var e = new cr.Event('select', false, false);
+      e.oldSelectionType = oldSelectionType;
+      this.dispatchEvent(e);
     },
 
     /**
      * Updates the preview image, if present.
      * @private
      */
     updatePreview_: function() {
       var url = this.selectedItemUrl;
       if (url && this.previewImage_)
         this.previewImage_.src = url;
@@ skipping 41 matching lines @@
      *     delay.
      */
     checkCameraPresence: function(onAvailable, onAbsent) {
       this.cameraOnline = false;
       if (this.cameraPresentCheckTimer_) {
         clearTimeout(this.cameraPresentCheckTimer_);
         this.cameraPresentCheckTimer_ = null;
       }
       if (!this.cameraVideo_)
         return;
+      this.cameraCheckInProgress_ = true;
       navigator.webkitGetUserMedia(
           {video: true},
           this.handleCameraAvailable_.bind(this, onAvailable),
           // Needs both arguments since it may call checkCameraPresence again.
           this.handleCameraAbsent_.bind(this, onAvailable, onAbsent));
     },
 
     /**
      * Stops camera capture, if it's currently active.
      */
     stopCamera: function() {
       this.cameraOnline = false;
       if (this.cameraVideo_)
         this.cameraVideo_.src = '';
+      // Cancel any pending getUserMedia() checks.
+      this.cameraCheckInProgress_ = false;
     },
 
     /**
      * Handles successful camera check.
      * @param {function(): boolean} onAvailable Callback to call. If it returns
      *     |true|, capture is started immediately.
      * @param {MediaStream} stream Stream object as returned by getUserMedia.
      * @private
      */
     handleCameraAvailable_: function(onAvailable, stream) {
       this.cameraPresent = true;
-      if (onAvailable())
+      if (this.cameraCheckInProgress_ && onAvailable())
         this.cameraVideo_.src = window.webkitURL.createObjectURL(stream);
+      this.cameraCheckInProgress_ = false;
     },
 
     /**
      * Handles camera check failure.
      * @param {function(): boolean} onAvailable Callback that is called if
      *     camera is available in future re-checks. If it returns |true|,
      *     capture is started immediately.
      * @param {function(): boolean} onAbsent Callback to call. If it returns
      *     |true|, camera is checked again after some delay.
      * @param {NavigatorUserMediaError=} err Error object.
      * @private
      */
     handleCameraAbsent_: function(onAvailable, onAbsent, err) {
       this.cameraPresent = false;
       this.cameraOnline = false;
       if (onAbsent()) {
         // Repeat the check.
         this.cameraPresentCheckTimer_ = setTimeout(
             this.checkCameraPresence.bind(this, onAvailable, onAbsent),
             CAMERA_CHECK_INTERVAL_MS);
       }
+      this.cameraCheckInProgress_ = false;
     },
 
     /**
      * Handles successful camera capture start.
      * @private
      */
     handleVideoStarted_: function() {
       this.cameraOnline = true;
       this.handleVideoUpdate_();
     },
@@ skipping 143 matching lines @@
     },
     set previewElement(value) {
       this.previewElement_ = value;
       this.previewImage_ = value.querySelector('img');
       this.cameraVideo_ = value.querySelector('video');
       this.cameraVideo_.addEventListener('canplay',
                                          this.handleVideoStarted_.bind(this));
       this.cameraVideo_.addEventListener('timeupdate',
                                          this.handleVideoUpdate_.bind(this));
       this.updatePreview_();
+      this.checkCameraPresence(
+          function() {
+            return false;  // Don't start streaming if camera is present.
+          },
+          function() {
+            return false;  // Don't retry if camera is absent.
+          });
     },
 
     /**
      * Whether the camera live stream and photo should be flipped horizontally.
      * @type {boolean}
      */
     get flipPhoto() {
       return this.flipPhoto_ || false;
     },
     set flipPhoto(value) {
@@ skipping 221 matching lines @@
   UserImagesGrid.ButtonImages = {
     TAKE_PHOTO: 'chrome://theme/IDR_BUTTON_USER_IMAGE_TAKE_PHOTO',
     CHOOSE_FILE: 'chrome://theme/IDR_BUTTON_USER_IMAGE_CHOOSE_FILE',
     PROFILE_PICTURE: 'chrome://theme/IDR_PROFILE_PICTURE_LOADING'
   };
 
   return {
     UserImagesGrid: UserImagesGrid
   };
 });