Changed look of pin keyboard.

chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js

Index: chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
diff --git a/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js b/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
index b8cc285318f957bbd2b9e438486fcd6067ab7e85..dfc111d4c5fcd7c32df8aa1e7a95762d0894bfbb 100644
--- a/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
+++ b/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
@@ -62,6 +62,13 @@ Polymer({
       this.fire('pin-change', { pin: value });
   },
 
+  /** Called when the user wants to erase the last character of the entered
+   *  PIN value.
+   */
+  onPinClear_: function() {
+    this.value = this.value.substring(0, this.value.length - 1);
+  },
+
   /** Called when a key event is pressed while the input element has focus. */
   onInputKeyDown_: function(event) {
     // Up/down pressed, swallow the event to prevent the input value from