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

chrome/browser/resources/settings/internet_page/network_siminfo.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 Polymer element for displaying and modifying cellular sim info.
  */
 (function() {
 
 /** @enum {string} */
@@ skipping 127 matching lines @@
         this.$.enterPin.inputElement.select();
       } else {
         this.error_ = ErrorType.NONE;
         this.$.enterPinDialog.close();
       }
     }.bind(this));
   },
 
   /**
    * Opens the Change PIN dialog.
-   * @param {Event} event
+   * @param {!Event} event
    * @private
    */
   onChangePinTap_: function(event) {
     if (!this.networkProperties || !this.networkProperties.Cellular)
       return;
+    event.preventDefault();
     this.error_ = ErrorType.NONE;
     this.$.changePinDialog.showModal();
     this.$.changePinOld.value = '';
     this.$.changePinNew1.value = '';
     this.$.changePinNew2.value = '';
   },
 
   /**
    * Sends the old and new PIN values from the Change PIN dialog.
    * @param {Event} event
@@ skipping 16 matching lines @@
         this.$.changePinOld.inputElement.select();
       } else {
         this.error_ = ErrorType.NONE;
         this.$.changePinDialog.close();
       }
     }.bind(this));
   },
 
   /**
    * Opens the Unlock PIN dialog.
-   * @param {Event} event
+   * @param {!Event} event
    * @private
    */
   onUnlockPinTap_: function(event) {
+    event.preventDefault();
     this.error_ = ErrorType.NONE;
     this.$.unlockPinDialog.showModal();
     this.$.unlockPin.value = '';
   },
 
   /**
    * Sends the PIN value from the Unlock PIN dialog.
    * @param {Event} event
    * @private
    */
@@ skipping 132 matching lines @@
    */
   validatePuk_: function(puk) {
     if (puk.length < PUK_MIN_LENGTH) {
       this.error_ = ErrorType.INVALID_PUK;
       return false;
     }
     return true;
   }
 });
 })();