Lock screen pin keyboard ui upgrades.

chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.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
  * 'pin-keyboard' is a keyboard that can be used to enter PINs or more generally
  * numeric values.
  *
  * Properties:
@@ skipping 29 matching lines @@
     },
 
     /**
      * Whether or not the keyboard's submit button should be shown.
      */
     enableSubmitButton: {
       type: Boolean,
       value: false
     },
 
+    /**
+     * Whether or not the keyboard's input has anything entered.
+     */
+    hasContent: {

[jdufault, 2016/08/26 01:24:12]

It doesn't look like this property ever gets updated. Either way, use a function
instead of a property so you can declare the dependency inside of the html.

Can you also apply this treatment to all of the other functions which follow the
pattern

  function foo(a) {
    return a ? 'class' : '';
  }

[sammiequon, 2016/08/26 19:56:38]

Done.

+      type: Boolean,
+      value: false
+    },
+
     /** The value stored in the keyboard's input element. */
     value: {
       type: String,
       notify: true,
       value: '',
       observer: 'onPinValueChange_'
     }
   },
 
   /**
@@ skipping 60 matching lines @@
 
     // Enter pressed.
     if (event.keyCode == 13) {
       this.firePinSubmitEvent_();
       event.preventDefault();
       return;
     }
   },
 
   /**
-   * Changes the color of the submit button if PIN is ready.
+   * Disables the submit and backspace button if nothing is entered.
    * @param {string} value
    * @private
    */
-  getSubmitClass_: function(value) {
-    return value.length > 0 ? 'ready-background' : '';
+  hasInput_: function(value) {
+    return value.length > 0;
   },
 
   /**
    * Computes whether the input type for the pin input should be password or
    * numerical.
    * @param {boolean} enablePassword
    * @private
    */
   getInputType_: function(enablePassword) {
     return enablePassword ? 'password' : 'number';
@@ skipping 25 matching lines @@
     // (just numbers), if the document direction is rtl.
     var enableRtl = (document.dir == 'rtl') && !Number.isInteger(+password);
     return enableRtl ? 'input-non-pin' : '';
   },
 
   /**
    * Computes if the submit button is visible.
    * @param {boolean} submitEnabled
    * @private
    */
-  getSubmitHiddenClass_: function(submitEnabled) {
+  getSubmitClass_: function(submitEnabled) {
     return submitEnabled ? '' : 'submit-button-hidden';
   }
 });