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

ui/file_manager/file_manager/foreground/js/quick_view_controller.js

Index: ui/file_manager/file_manager/foreground/js/quick_view_controller.js
diff --git a/ui/file_manager/file_manager/foreground/js/quick_view_controller.js b/ui/file_manager/file_manager/foreground/js/quick_view_controller.js
index 1b8e182b64088b4ddf28907da85aabb0ae6933cc..c97d6c92f802c6d01feb3a5ec37acd5915508bc5 100644
--- a/ui/file_manager/file_manager/foreground/js/quick_view_controller.js
+++ b/ui/file_manager/file_manager/foreground/js/quick_view_controller.js
@@ -255,7 +255,7 @@ QuickViewController.prototype.onFileSelectionChanged_ = function(event) {
 
 /**
  * @param {!FileEntry} entry
- * @return {!Promise<!Array<!FileTask>>}
+ * @return {!Promise<!Array<!chrome.fileManagerPrivate.FileTask>>}
  * @private
  */
 QuickViewController.prototype.getAvailableTasks_ = function(entry) {
@@ -291,8 +291,9 @@ QuickViewController.prototype.updateQuickView_ = function() {
         this.getAvailableTasks_(entry)
       ])
       .then(function(values) {
-        var items = (/**@type{Array<MetadataItem>}*/ (values[0]));
-        var tasks = (/**@type{!Array<!FileTask>}*/ (values[1]));
+        var items = /**@type{Array<MetadataItem>}*/ (values[0]);
+        var tasks = /**@type{!Array<!chrome.fileManagerPrivate.FileTask>}*/ (
+            values[1]);
         return this.onMetadataLoaded_(entry, items, tasks);
       }.bind(this))
       .catch(console.error);
@@ -303,7 +304,7 @@ QuickViewController.prototype.updateQuickView_ = function() {
  *
  * @param {!FileEntry} entry
  * @param {Array<MetadataItem>} items
- * @param {!Array<!FileTask>} tasks
+ * @param {!Array<!chrome.fileManagerPrivate.FileTask>} tasks
  * @private
  */
 QuickViewController.prototype.onMetadataLoaded_ = function(
@@ -337,7 +338,7 @@ var QuickViewParams;
 /**
  * @param {!FileEntry} entry
  * @param {Array<MetadataItem>} items
- * @param {!Array<!FileTask>} tasks
+ * @param {!Array<!chrome.fileManagerPrivate.FileTask>} tasks
  * @return !Promise<!QuickViewParams>
  *
  * @private