Integrate ListThumbnailLoader to list view and grid view.

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

Index: ui/file_manager/file_manager/foreground/js/file_manager.js
diff --git a/ui/file_manager/file_manager/foreground/js/file_manager.js b/ui/file_manager/file_manager/foreground/js/file_manager.js
index f677f160bab324d5120c4af9c6ee08706acc0434..7b9128346bf047038b3476220bdc938614293da0 100644
--- a/ui/file_manager/file_manager/foreground/js/file_manager.js
+++ b/ui/file_manager/file_manager/foreground/js/file_manager.js
@@ -884,6 +884,8 @@ FileManager.prototype = /** @struct */ {
     // attach the directory model.
     this.initDirectoryTree_();
 
+    this.ui_.listContainer.listThumbnailLoader = new ListThumbnailLoader(
+        assert(this.directoryModel_.getFileList()), this.metadataCache_);
     this.ui_.listContainer.dataModel = this.directoryModel_.getFileList();
     this.ui_.listContainer.selectionModel =
         this.directoryModel_.getFileListSelection();