Add custom action support

third_party/closure_compiler/externs/automation.js

Index: third_party/closure_compiler/externs/automation.js
diff --git a/third_party/closure_compiler/externs/automation.js b/third_party/closure_compiler/externs/automation.js
index 128d92feb3eaf68d198f9a6ba9be246ed995741b..fc20a1fe26fb1d07af494794b957647bf5bf0740 100644
--- a/third_party/closure_compiler/externs/automation.js
+++ b/third_party/closure_compiler/externs/automation.js
@@ -366,6 +366,15 @@ chrome.automation.TreeChangeObserverFilter = {
   ALL_TREE_CHANGES: 'allTreeChanges',
 };
 
+/**
+ * @typedef {{

[Devlin, 2017/06/14 18:23:10]

were these just generated through the script?

[yawano, 2017/06/15 10:43:21]

Yes, this is generated by tools/json_schema_compiler/compiler.py script.

+ *   id: number,
+ *   description: string
+ * }}
+ * @see https://developer.chrome.com/extensions/automation#type-CustomAction
+ */
+chrome.automation.CustomAction;
+
 /**
  * @constructor
  * @private
@@ -531,6 +540,13 @@ chrome.automation.AutomationNode.prototype.activeDescendant;
  */
 chrome.automation.AutomationNode.prototype.inPageLinkTarget;
 
+/**
+ * An array of custom actions.
+ * @type {(!Array<!chrome.automation.CustomAction>|undefined)}
+ * @see https://developer.chrome.com/extensions/automation#type-customActions
+ */
+chrome.automation.AutomationNode.prototype.customActions;
+
 /**
  * The URL that this link will navigate to.
  * @type {(string|undefined)}
@@ -1048,6 +1064,13 @@ chrome.automation.AutomationNode.prototype.hitTest = function(x, y, eventToFire)
  */
 chrome.automation.AutomationNode.prototype.makeVisible = function() {};
 
+/**
+ * Performs custom action.
+ * @param {number} customActionId
+ * @see https://developer.chrome.com/extensions/automation#method-performCustomAction
+ */
+chrome.automation.AutomationNode.prototype.performCustomAction = function(customActionId) {};
+
 /**
  * Sets selection within a text field.
  * @param {number} startIndex