login-webui: Close any bubble when window loses focus.

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

Index: chrome/browser/resources/chromeos/login/bubble.js
diff --git a/chrome/browser/resources/chromeos/login/bubble.js b/chrome/browser/resources/chromeos/login/bubble.js
index b7b9e6442525ed68630394d0a016cf0caeedbf95..492686ae907ff856a0c22b4be7f6fe96ff9430e5 100644
--- a/chrome/browser/resources/chromeos/login/bubble.js
+++ b/chrome/browser/resources/chromeos/login/bubble.js
@@ -38,6 +38,7 @@ cr.define('cr.ui', function() {
                                           this.handleDocClick_.bind(this));
       this.ownerDocument.addEventListener('keydown',
                                           this.handleDocKeyDown_.bind(this));
+      window.addEventListener('blur', this.handleWindowBlur_.bind(this));
       this.addEventListener('webkitTransitionEnd',
                             this.handleTransitionEnd_.bind(this));
     },
@@ -215,6 +216,15 @@ cr.define('cr.ui', function() {
     handleDocKeyDown_: function(e) {
       if (!this.hidden)
         this.hide();
+    },
+
+    /**
+     * Handler of window blur event.
+     * @private
+     */
+    handleWindowBlur_: function(e) {
+      if (!this.hidden)
+        this.hide();
     }
   };