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

ui/file_manager/gallery/js/gallery.js

Index: ui/file_manager/gallery/js/gallery.js
diff --git a/ui/file_manager/gallery/js/gallery.js b/ui/file_manager/gallery/js/gallery.js
index 79cae82a7e9e5005d5cdd7197ff033f1f57fe77e..9d98447cc8785888d5a137d09df3c29d6c0f7038 100644
--- a/ui/file_manager/gallery/js/gallery.js
+++ b/ui/file_manager/gallery/js/gallery.js
@@ -758,16 +758,20 @@ Gallery.prototype.onKeyDown_ = function(event) {
   // Handle debug shortcut keys.
   switch (keyString) {
     case 'Ctrl-Shift-I': // Ctrl+Shift+I
-      chrome.fileManagerPrivate.openInspector('normal');
+      chrome.fileManagerPrivate.openInspector(
+          chrome.fileManagerPrivate.InspectionType.NORMAL);
       break;
     case 'Ctrl-Shift-J': // Ctrl+Shift+J
-      chrome.fileManagerPrivate.openInspector('console');
+      chrome.fileManagerPrivate.openInspector(
+          chrome.fileManagerPrivate.InspectionType.CONSOLE);
       break;
     case 'Ctrl-Shift-C': // Ctrl+Shift+C
-      chrome.fileManagerPrivate.openInspector('element');
+      chrome.fileManagerPrivate.openInspector(
+          chrome.fileManagerPrivate.InspectionType.ELEMENT);
       break;
     case 'Ctrl-Shift-B': // Ctrl+Shift+B
-      chrome.fileManagerPrivate.openInspector('background');
+      chrome.fileManagerPrivate.openInspector(
+          chrome.fileManagerPrivate.InspectionType.BACKGROUND);
       break;
   }