Added strings of i18n and made the pin-keyboard work for rtl lang.

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 dfc111d4c5fcd7c32df8aa1e7a95762d0894bfbb..344b5c02400a66cba0eafecf2828129c85a5bc15 100644
--- a/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
+++ b/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
@@ -25,7 +25,20 @@
 Polymer({
   is: 'pin-keyboard',
 
+  behaviors: [
+    I18nBehavior,
+  ],
+
   properties: {
+    /**
+     * Whether or not the keyboard's input element should be numerical
+     * or password.
+     */
+    enablePassword: {
+      type: Boolean,
+      value: false
+    },
+
     /** The value stored in the keyboard's input element. */
     value: {
       type: String,
@@ -84,5 +97,40 @@ Polymer({
       event.preventDefault();
       return;
     }
+  },
+
+  /**
+   * Computes whether the input type for the pin input should be password or
+   * numerical.
+   * @private
+   */
+  computeInputType_: function(enablePassword) {
+    return enablePassword ? 'password' : 'number';
+  },
+
+  /**
+   * Computes the value of the pin input placeholder.
+   * @private
+   */
+  computeInputPlaceholder_: function(enablePassword) {
+    return enablePassword ? this.i18n('pinKeyboardPlaceholderPinPassword') :
+                            this.i18n('pinKeyboardPlaceholderPin');
+  },
+
+  /**
+   * Computes the direction of the pin input.
+   * @private
+   */
+  computeInputClass_: function(password) {
+    // +password will convert a string to a number or to NaN if that's not
+    // possible. Number.isInteger will verify the value is not a NaN and that it
+    // does not contain decimals.
+    // This heuristic will fail for inputs like '1.0'.
+    //
+    // Since we still support users entering their passwords through the PIN
+    // keyboard, we swap the input box to rtl when we think it is a password

[jdufault, 2016/07/01 18:26:54]

The comment I meant was along the lines of the why ltr is on the document root.
You can revert this comment to the original.

So add a cleaned up version of the below to pin_keyboard.html around line 14:

  Add ltr on the root element because the PIN keyboard should always be laid out

  ltr regardless of the language. However, if the user is entering a password,
the 
  password should be rtl, which is implemented by dynamically adding/removing
the 
  input-non-pin class.
  
This also makes me think that input-non-pin should always be added and the rtl
check should happen inside the CSS. Though if that's a lot of work it's fine as
is.

+    // (just numbers), if the document direction is rtl.
+    var enableRtl = (document.dir == 'rtl') && !Number.isInteger(+password);
+    return enableRtl ? 'input-non-pin' : '';
   }
 });