Pin keyboard use enter to submit when focus is not on a button.

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 de93c08df1b17741ac5612be76bb7a37cf141619..f478e854e88f462cddc4c5e3a216708def058f74 100644
--- a/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
+++ b/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
@@ -57,6 +57,13 @@ Polymer({
   onNumberTap_: function(event, detail) {
     var numberValue = event.target.getAttribute('value');
     this.value += numberValue;
+
+    // If a number button is clicked, we do not want to switch focus to the
+    // button, therefore we transfer focus back to the input, but if a number
+    // button is tabbed into, it should keep focus, so users can use tab and
+    // spacebar/return to enter their PIN.
+    if (!event.target.classList.contains('keyboard-focus'))

[jdufault, 2016/07/12 19:59:44]

What about just casting event.target to the right type?

Checking the active class state seems like a pretty round-about way to do this.

+      this.focus();
   },
 
   /** Fires a submit event with the current PIN value. */