[Media Router WebUI] Show issue's secondary action when 'dismiss'.

chrome/browser/resources/media_router/elements/issue_banner/issue_banner.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.
 
 // This Polymer element is used to show information about issues related
 // to casting.
 Polymer({
   is: 'issue-banner',
 
   properties: {
@@ skipping 62 matching lines @@
 
     return issue.isBlocking ? 'blocking' : 'non-blocking';
   },
 
   /**
    * @param {?media_router.Issue} issue
    * @return {boolean} Whether or not to hide the non-blocking issue UI.
    * @private
    */
   computeOptionalActionHidden_: function(issue) {
-    return !issue || !issue.secondaryActionType;
+    return !issue || issue.secondaryActionType === undefined;
   },
 
   /**
    * Fires an issue-action-click event.
    *
    * @param {number} actionType The type of issue action.
    * @private
    */
   fireIssueActionClick_: function(actionType) {
     this.fire('issue-action-click', {
@@ skipping 31 matching lines @@
    * @private
    */
   updateActionButtonText_: function() {
     var defaultText = '';
     var secondaryText = '';
     if (this.issue) {
       defaultText =
           this.i18n(this.actionTypeToButtonTextResource_[
               this.issue.defaultActionType]);
 
-      if (this.issue.secondaryActionType) {
+      if (this.issue.secondaryActionType !== undefined) {
         secondaryText =
             this.i18n(this.actionTypeToButtonTextResource_[
                 this.issue.secondaryActionType]);
       }
     }
 
     this.defaultActionButtonText_ = defaultText;
     this.secondaryActionButtonText_ = secondaryText;
   },
 });