Merge to m57: Improve live region performance

chrome/browser/resources/chromeos/chromevox/cvox2/background/live_regions.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 Implements support for live regions in ChromeVox Next.
  */
 
 goog.provide('LiveRegions');
 
@@ skipping 110 matching lines @@
    * live region description.
    * @param {!AutomationNode} node The changed node.
    * @param {?string=} opt_prependFormatStr If set, a format string for
    *     cvox2.Output to prepend to the output.
    * @private
    */
   outputLiveRegionChange_: function(node, opt_prependFormatStr) {
     if (node.containerLiveBusy)
       return;
 
-    if (node.containerLiveAtomic && !node.liveAtomic) {
-      if (node.parent)
-        this.outputLiveRegionChange_(node.parent, opt_prependFormatStr);
+    var delta = new Date() - this.lastLiveRegionTime_;
+    if (delta > LiveRegions.LIVE_REGION_MIN_SAME_NODE_MS)
+      this.liveRegionNodeSet_ = new WeakSet();
+
+    while (node.containerLiveAtomic && !node.liveAtomic && node.parent)
+      node = node.parent;
+
+    if (this.liveRegionNodeSet_.has(node)) {
+      this.lastLiveRegionTime_ = new Date();
       return;
     }
 
-    // Alerts should be announced as a result of focus.
-    if (node.role == RoleType.alert)
-      return;
+    this.outputLiveRegionChangeForNode_(node, opt_prependFormatStr);
+  },
 
+  /**
+   * @param {!AutomationNode} node The changed node.
+   * @param {?string=} opt_prependFormatStr If set, a format string for
+   *     cvox2.Output to prepend to the output.
+   * @private
+   */
+  outputLiveRegionChangeForNode_: function(node, opt_prependFormatStr) {
     var range = cursors.Range.fromNode(node);
     var output = new Output();
     if (opt_prependFormatStr)
       output.format(opt_prependFormatStr);
     output.withSpeech(range, range, Output.EventType.NAVIGATE);
 
     if (!output.hasSpeech && node.liveAtomic)
       output.format('$joinedDescendants', node);
 
     output.withSpeechCategory(cvox.TtsCategory.LIVE);
@@ skipping 10 matching lines @@
 
     // Enqueue live region updates that were received at approximately
     // the same time, otherwise flush previous live region updates.
     var queueTime = LiveRegions.LIVE_REGION_QUEUE_TIME_MS;
     var delta = currentTime - this.lastLiveRegionTime_;
     if (delta > queueTime && !forceQueueForBackgroundedLiveRegion)
       output.withQueueMode(cvox.QueueMode.CATEGORY_FLUSH);
     else
       output.withQueueMode(cvox.QueueMode.QUEUE);
 
-    if (delta > LiveRegions.LIVE_REGION_MIN_SAME_NODE_MS)
-      this.liveRegionNodeSet_ = new WeakSet();
-
-    var parent = node;
-    while (parent) {
-      if (this.liveRegionNodeSet_.has(parent)) {
-        this.lastLiveRegionTime_ = currentTime;
-        return;
-      }
-      parent = parent.parent;
-    }
-
     this.liveRegionNodeSet_.add(node);
     output.go();
     this.lastLiveRegionTime_ = currentTime;
   },
 };
 
 });  // goog.scope