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..e2fc832ac4568c5a7064ed84af6c02c4f3ab0682 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 +97,37 @@ Polymer({
       event.preventDefault();
       return;
     }
+  },
+
+  /**
+   * @private

[xiyuan, 2016/06/30 22:54:14]

nit: move this to the end of jsdoc, here and other places.

+   * Computes whether the input type for the pin input should be password or
+   * numerical.
+   */
+  computeInputType_: function(enablePassword) {
+    return enablePassword ? 'password' : 'number';
+  },
+
+  /**
+   * @private
+   * Computes the value of the pin input placeholder.
+   */
+  computeInputPlaceholder_: function(enablePassword) {
+    return enablePassword ? this.i18n('pinKeyboardPlaceholderPinPassword') :
+                            this.i18n('pinKeyboardPlaceholderPin');
+  },
+
+  /**
+   * @private
+   * Computes the direction of the pin input.
+   */
+  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'.
+    var enableRtl = (document.dir == 'rtl') && !Number.isInteger(+password);
+    return enableRtl ? 'input-non-pin' : '';

[xiyuan, 2016/06/30 22:54:14]

I am not quite follow. What are we trying to do here? Switching to RTL when
input is not a number? If so, what happens when Chrome uses a RTL lang such as
"ar"?

[jdufault, 2016/06/30 22:58:19]

The complication here is that the PIN keyboard accepts both a password and a
PIN.

If the user is entering a PIN, input should always be LTR.

If the user is entering a password, input should be RTL in RTL languages.

[xiyuan, 2016/06/30 23:09:34]

emm, would the default behavior of number input work properly? Think chrome
should handle bidi and show numbers as LTR. Why we need to explicitly set to LTR
for pin input? 

And with "direction: ltr" on #root, would that work properly for the digit
buttons on rtl?

   }
 });