drive: Stop making multiple GetAppList() requests from DriveAppRegistry

chrome/browser/chromeos/drive/drive_app_registry.h

Index: chrome/browser/chromeos/drive/drive_app_registry.h
diff --git a/chrome/browser/chromeos/drive/drive_app_registry.h b/chrome/browser/chromeos/drive/drive_app_registry.h
index 935c61a01be3f0f1f75ed6f0acc10cabea144131..2b89a41db26fcb56c803f26bb86d92452c99aa68 100644
--- a/chrome/browser/chromeos/drive/drive_app_registry.h
+++ b/chrome/browser/chromeos/drive/drive_app_registry.h
@@ -22,7 +22,7 @@ class FilePath;
 
 namespace google_apis {
 class AppList;
-}  // namespace AppList
+}  // namespace google_apis
 
 namespace drive {
 
@@ -145,6 +145,8 @@ class DriveAppRegistry {
   // Map of MIME type to application info.
   DriveAppFileSelectorMap app_mimetypes_map_;
 
+  bool is_updating_;
+
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate the weak pointers before any other members are destroyed.
   base::WeakPtrFactory<DriveAppRegistry> weak_ptr_factory_;