Call preventDefault in all on-tap events that show a dialog.

chrome/browser/resources/settings/device_page/storage.js

 // Copyright 2016 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-storage' is the settings subpage for storage settings.
  */
 cr.exportPath('settings');
 
@@ skipping 97 matching lines @@
   /**
    * Handler for tapping the "Downloads" item.
    * @private
    */
   onDownloadsTap_: function() {
     chrome.send('openDownloads');
   },
 
   /**
    * Handler for tapping the "Offline files" item.
+   * @param {!Event} e
    * @private
    */
-  onDriveCacheTap_: function() {
+  onDriveCacheTap_: function(e) {
+    e.preventDefault();
     this.$.storageDriveCache.open();
   },
 
   /**
    * Handler for tapping the "Browsing data" item.
    * @private
    */
   onBrowsingDataTap_: function() {
     settings.navigateTo(settings.Route.CLEAR_BROWSER_DATA);
   },
@@ skipping 142 matching lines @@
     switch (spaceState) {
       case settings.StorageSpaceState.LOW:
         return 'space-low';
       case settings.StorageSpaceState.CRITICALLY_LOW:
         return 'space-critically-low';
       default:
         return '';
     }
   },
 });