MD Settings: Skip unseen collapse animation

chrome/browser/resources/settings/settings_page/settings_section.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-section' shows a paper material themed section with a header
  * which shows its page title.
  *
  * The section can expand vertically to fill its container's padding edge.
@@ skipping 121 matching lines @@
     animation.finished.then(function() {
       this.classList.add('expanded');
     }.bind(this), function() {}).then(function() {
       // Unset these changes whether the animation finished or canceled.
       this.classList.remove('expanding');
       this.style.height = '';
     }.bind(this));
     return animation;
   },
 
-  /** @return {boolean} True if the section is currently expanded. */
+  /**
+   * @return {boolean} True if the section is currently expanded and we know
+   *     what the collapsed height should be.
+   */
   canAnimateCollapse: function() {
     return this.classList.contains('expanded') && this.clientHeight > 0 &&
         !Number.isNaN(this.collapsedHeight_);
   },
 
   /**
    * Prepares for the animation before the other sections become visible.
    * Call before animateCollapse().
    * @param {!HTMLElement} container
    */
@@ skipping 90 matching lines @@
 
     var options = /** @type {!KeyframeEffectOptions} */({
       duration: settings.animation.Timing.DURATION,
       easing: settings.animation.Timing.EASING,
     });
 
     return new settings.animation.Animation(
         this.$.card, [startFrame, endFrame], options);
   },
 });