automation_custom_bindings needs to handle blur events too.

chrome/renderer/resources/extensions/automation_custom_bindings.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Custom bindings for the automation API.
 var AutomationNode = require('automationNode').AutomationNode;
 var AutomationRootNode = require('automationNode').AutomationRootNode;
 var automation = require('binding').Binding.create('automation');
 var automationInternal =
     require('binding').Binding.create('automationInternal').generate();
@@ skipping 260 matching lines @@
 
 /**
  * Dispatch accessibility events fired on individual nodes to its
  * corresponding AutomationNode. Handle focus events specially
  * (see below).
  */
 automationInternal.onAccessibilityEvent.addListener(function(eventParams) {
   var id = eventParams.treeID;
   var targetTree = AutomationRootNode.getOrCreate(id);
 
+  // Work around an issue where Chrome sends us 'blur' events on the
+  // root node when nothing has focus, we need to treat those as focus
+  // events but otherwise not handle blur events specially.
+  var isFocusEvent = false;
+  if (eventParams.eventType == schema.EventType.focus) {
+    isFocusEvent = true;
+  } else if (eventParams.eventType == schema.EventType.blur) {
+    var node = privates(targetTree).impl.get(eventParams.targetID);
+    if (node == node.root)
+      isFocusEvent = true;
+  }
+
   // When we get a focus event, ignore the actual event target, and instead
   // check what node has focus globally. If that represents a focus change,
   // fire a focus event on the correct target.
-  if (eventParams.eventType == schema.EventType.focus) {
+  if (isFocusEvent) {
     var previousFocusedNode = automationUtil.focusedNode;
     automationUtil.updateFocusedNode();
     if (automationUtil.focusedNode &&
         automationUtil.focusedNode == previousFocusedNode) {
       return;
     }
 
     if (automationUtil.focusedNode) {
       targetTree = automationUtil.focusedNode.root;
       eventParams.treeID = privates(targetTree).impl.treeID;
@@ skipping 42 matching lines @@
 
 var binding = automation.generate();
 // Add additional accessibility bindings not specified in the automation IDL.
 // Accessibility and automation share some APIs (see
 // ui/accessibility/ax_enums.idl).
 forEach(schema, function(k, v) {
   binding[k] = v;
 });
 
 exports.$set('binding', binding);