cros: Fix header bar not showing up on lock screen.

chrome/browser/resources/chromeos/login/header_bar.js

Index: chrome/browser/resources/chromeos/login/header_bar.js
diff --git a/chrome/browser/resources/chromeos/login/header_bar.js b/chrome/browser/resources/chromeos/login/header_bar.js
index 85aff7239d655b7eefb6373a2ff4615825352369..abffe5f782e3ff5f9f787c50d5084ba25aa4ca94 100644
--- a/chrome/browser/resources/chromeos/login/header_bar.js
+++ b/chrome/browser/resources/chromeos/login/header_bar.js
@@ -226,6 +226,20 @@ cr.define('login', function() {
     },
   };
 
+  /**
+   * Convenience wrapper of animateOut.
+   */
+  HeaderBar.animateOut = function(callback) {
+    $('login-header-bar').animateOut(callback);
+  };
+
+  /**
+   * Convenience wrapper of animateIn.
+   */
+  HeaderBar.animateIn = function() {
+    $('login-header-bar').animateIn();
+  }
+
   return {
     HeaderBar: HeaderBar
   };