Fix developer_private.js for closure compiler

Automated definition used enum types instead of strings, and it looks like we
need to include the two functions which take "any" arguments.

BUG=461039

Review URL: https://codereview.chromium.org/956063002

Cr-Commit-Position: refs/heads/master@{#318143}

third_party/closure_compiler/externs/developer_private.js

@@ -4,7 +4,13 @@
 
 /** @fileoverview Externs generated from namespace: developerPrivate */
 
-// Note: hand-modified to change Array to !Array in ItemInfo typedef.
+// Note: hand-modified to change Array to !Array in ItemInfo typedef, and add
+// typedef {string} for idl enums.
+
+/**
+ * @typedef {string}
+ */
+var ItemType;
 
 /**
  * @typedef {{
@@ -68,6 +74,26 @@ var ItemInfo;
  */
 var InspectOptions;
 
+/**
+ * @typedef {string}
+ */
+var PackStatus;
+
+/**
+ * @typedef {string}
+ */
+var FileType;
+
+/**
+ * @typedef {string}
+ */
+var SelectType;
+
+/**
+ * @typedef {string}
+ */
+var EventType;
+
 /**
  * @typedef {{
  *   message: string,
@@ -196,5 +222,19 @@ chrome.developerPrivate.packDirectory = function(path, private_key_path, flags,
  */
 chrome.developerPrivate.isProfileManaged = function(callback) {};
 
+/**
+ * Reads and returns the contents of a file related to an extension which
+ * caused an error.
+ * @param {?} dict
+ * @param {Function} callback
+ */
+chrome.developerPrivate.requestFileSource = function(dict, callback) {};
+
+/**
+ * Open the developer tools to focus on a particular error.
+ * @param {?} dict
+ */
+chrome.developerPrivate.openDevTools = function(dict) {};
+
 /** @type {!ChromeEvent} */
 chrome.developerPrivate.onItemStateChanged;