Fix some lingering WebUI focus issues.

chrome/browser/resources/extensions/extension_error_overlay.js

Index: chrome/browser/resources/extensions/extension_error_overlay.js
diff --git a/chrome/browser/resources/extensions/extension_error_overlay.js b/chrome/browser/resources/extensions/extension_error_overlay.js
index 84e32a9f63bb0fbf8b6f988b74978a0f683b93de..1f7975e6605c39366ae46d65b64c9953838df136 100644
--- a/chrome/browser/resources/extensions/extension_error_overlay.js
+++ b/chrome/browser/resources/extensions/extension_error_overlay.js
@@ -292,8 +292,10 @@ cr.define('extensions', function() {
       cr.ui.overlay.globalInitialization();
       overlay.addEventListener('cancelOverlay', this.handleDismiss_.bind(this));
 
-      $('extension-error-overlay-dismiss').addEventListener(
-          'click', this.handleDismiss_.bind(this));
+      $('extension-error-overlay-dismiss').addEventListener('click',
+          function() {
+        cr.dispatchSimpleEvent(overlay, 'cancelOverlay');
+      });
 
       /**
        * The element of the full overlay.