Split out non-auto-generatable externs from auto generated ones.

chrome/browser/resources/chromeos/chromevox/cvox2/background/base_automation_handler.js

Index: chrome/browser/resources/chromeos/chromevox/cvox2/background/base_automation_handler.js
diff --git a/chrome/browser/resources/chromeos/chromevox/cvox2/background/base_automation_handler.js b/chrome/browser/resources/chromeos/chromevox/cvox2/background/base_automation_handler.js
index 7aaa80150d84ad1fbfa73a1257d5b7fc3aa86dcf..f6a747df4dbbd5b90de21d13c152afbaef2a9250 100644
--- a/chrome/browser/resources/chromeos/chromevox/cvox2/background/base_automation_handler.js
+++ b/chrome/browser/resources/chromeos/chromevox/cvox2/background/base_automation_handler.js
@@ -9,6 +9,8 @@
 
 goog.provide('BaseAutomationHandler');
 
+goog.require('ChromeVoxAutomationEvent');
+
 goog.scope(function() {
 var AutomationEvent = chrome.automation.AutomationEvent;
 var AutomationNode = chrome.automation.AutomationNode;
@@ -21,6 +23,7 @@ var EventType = chrome.automation.EventType;
 BaseAutomationHandler = function(node) {
   /**
    * @type {!AutomationNode}
+   * @private
    */
   this.node_ = node;
 
@@ -32,7 +35,8 @@ BaseAutomationHandler.prototype = {
   /**
    * Adds an event listener to this handler.
    * @param {chrome.automation.EventType} eventType
-   * @param {!function(!AutomationEvent): void} eventCallback
+   * @param {function((!AutomationEvent|!ChromeVoxAutomationEvent)): void}
+   *     eventCallback
    * @protected
    */
   addListener_: function(eventType, eventCallback) {
@@ -55,7 +59,7 @@ BaseAutomationHandler.prototype = {
   },
 
   /**
-   * @return {!function(!AutomationEvent): void}
+   * @return {!function((!AutomationEvent|!ChromeVoxAutomationEvent)): void}
    * @private
    */
   makeListener_: function(callback) {