Show UI when a folder is empty.

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 bcac74a49f54359eb4f95a4a4c791275a69602b8..be95288b4d7ce390cc01e212dfacb2c7b792b5d0 100644
--- a/ui/file_manager/file_manager/foreground/js/file_manager.js
+++ b/ui/file_manager/file_manager/foreground/js/file_manager.js
@@ -186,6 +186,12 @@ function FileManager() {
   this.toolbarController_ = null;
 
   /**
+   * Empty folder controller.
+   * @private {EmptyFolderController}
+   */
+  this.emptyFolderController_ = null;
+
+  /**
    * App state controller.
    * @type {AppStateController}
    * @private
@@ -428,6 +434,9 @@ FileManager.prototype = /** @struct */ {
         assert(this.ui_.locationLine),
         this.selectionHandler_,
         this.directoryModel_);
+    this.emptyFolderController_ = new EmptyFolderController(
+        this.ui_.emptyFolder,
+        this.directoryModel_);
 
     importer.importEnabled().then(
         function(enabled) {