Added mojo changes for supporting drivefs folder_features to chromium.

This brings across the changes made inside chromeos to the mojom that is
defined in chromium.

Bug: 884020
Change-Id: Iab4d789cf153fabbf8d243fd346e2188e9c4153b
Reviewed-on: https://chromium-review.googlesource.com/c/1321652Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Stuart Langley <slangley@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605952}

chromeos/components/drivefs/mojom/drivefs.mojom

@@ -152,6 +152,7 @@ struct DriveError {
   mojo_base.mojom.FilePath path;
 };
 
+// Next MinVersion: 2
 struct FileMetadata {
   enum Type {
     // A regular file.
@@ -193,6 +194,8 @@ struct FileMetadata {
   array<uint8>? deprecated_thumbnail;
 
   Capabilities capabilities;
+
+  [MinVersion=1] FolderFeature? folder_feature;
 };
 
 struct ImageMetadata {
@@ -213,6 +216,20 @@ struct Capabilities {
   bool can_add_children = true;
 };
 
+// Set on Drive Uploader roots and optionally on select sub-folders.
+struct FolderFeature {
+  // Identifies a root directory of a machine sync, used for the backup and
+  // restore feature.
+  bool is_machine_root = false;
+
+  // Identifies a sync folder.
+  bool is_arbitary_sync_folder = false;
+
+  // Identifies an external media folder, that contains one time only uploads
+  // for USB devices, SD cards etc.
+  bool is_external_media = false;
+};
+
 struct ItemEvent {
   enum State {
     kQueued,