(WIP) Use generator to generate externs for chrome.fileManagerPrivate API.

ui/file_manager/file_manager/background/js/device_handler.js

Index: ui/file_manager/file_manager/background/js/device_handler.js
diff --git a/ui/file_manager/file_manager/background/js/device_handler.js b/ui/file_manager/file_manager/background/js/device_handler.js
index bbdb598e142d4eefddd34e5242aa39027d8ba3b9..4f211c3cdb502c16dc9b8f04613cd8dc4aadf72c 100644
--- a/ui/file_manager/file_manager/background/js/device_handler.js
+++ b/ui/file_manager/file_manager/background/js/device_handler.js
@@ -263,7 +263,7 @@ DeviceHandler.Notification.prototype.makeId_ = function(devicePath) {
 
 /**
  * Handles notifications from C++ sides.
- * @param {DeviceEvent} event Device event.
+ * @param {chrome.fileManagerPrivate.DeviceEvent} event Device event.
  * @private
  */
 DeviceHandler.prototype.onDeviceChanged_ = function(event) {
@@ -322,7 +322,8 @@ Object.freeze(DeviceHandler.MountStatus);
 
 /**
  * Handles mount completed events to show notifications for removable devices.
- * @param {MountCompletedEvent} event Mount completed event.
+ * @param {chrome.fileManagerPrivate.MountCompletedEvent} event Mount completed
+ *     event.
  * @private
  */
 DeviceHandler.prototype.onMountCompleted_ = function(event) {
@@ -427,7 +428,7 @@ DeviceHandler.prototype.onMountCompleted_ = function(event) {
 
 /**
  * Handles mount events.
- * @param {MountCompletedEvent} event
+ * @param {chrome.fileManagerPrivate.MountCompletedEvent} event
  * @private
  */
 DeviceHandler.prototype.onMount_ = function(event) {