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 109 matching lines @@
 
     // Enter pressed.
     if (event.keyCode == 13) {
       this.firePinSubmitEvent_();
       event.preventDefault();
       return;
     }
   },
 
   /**
-   * Changes the color of the submit button if PIN is ready.
+   * Changes the color of input text if a something is entered.

[jdufault, 2016/08/05 21:58:52]

What about:

Changes the color of the input text if it is not empty.

[sammiequon, 2016/08/05 23:34:50]

Done.

    * @param {string} value
    * @private
    */
-  getSubmitClass_: function(value) {
+  getPasswordReadyClass_: function(value) {
     return value.length > 0 ? 'ready-background' : '';
   },
 
   /**
+   * Disables the submit and backspace button if nothing is entered.
+   * @param {string} value
+   * @private
+   */
+  getButtonsDisabled_: function(value) {

[jdufault, 2016/08/05 21:58:52]

Rename to hasInput_

[sammiequon, 2016/08/05 23:34:50]

Done.

+    return value.length > 0 ? false : true;

[jdufault, 2016/08/05 21:58:51]

return value.length == 0;

[sammiequon, 2016/08/05 23:34:50]

Done.

+  },
+
+  /**
    * 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 22 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';
   }
 });