Update Media Router WebUI JSDocs.

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: {
     /**
      * The issue to show.
      * @type {?media_router.Issue}
      */
     issue: {
       type: Object,
       value: null,
     },
   },
 
   /**
-   * Returns true to hide the blocking issue UI, false to show it.
-   *
    * @param {?media_router.Issue} issue
+   * @return {boolean} Whether or not to hide the blocking issue UI.
    * @private
    */
   computeIsBlockingIssueHidden_: function(issue) {
     return !issue || !issue.isBlocking;
   },
 
   /**
    * Returns true to hide the non-blocking issue UI, false to show it.
    *
    * @param {?media_router.Issue} issue
    * @private
    */
   computeIsNonBlockingIssueHidden_: function(issue) {
     return !issue || issue.isBlocking;
   },
 
   /**
-   * Returns true to hide |issue|'s optional action, false to show it.
-   *
    * @param {?media_router.Issue} issue
+   * @return {boolean} Whether or not to hide the non-blocking issue UI.
    * @private
    */
   computeOptionalActionHidden_: function(issue) {
     return !issue || !issue.optActionText;
   },
 
   /**
    * Fires an issue-action-click event.
    *
    * @param {number} actionType The type of issue action.
@@ skipping 20 matching lines @@
   /**
    * Called when an optional issue action is clicked.
    *
    * @param {!Event} event The event object.
    * @private
    */
   onClickOptAction_: function(event) {
     this.fireIssueActionClick_(this.issue.optActionType);
   },
 });