Files app: Optionally add class files-ng to the document.body

Bug: 992821
Change-Id: Ie5aa584a617de40288d057544834bf4cc630515c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1918788Reviewed-by: Noel Gordon <noel@chromium.org>
Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
Auto-Submit: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/master@{#715614}

ui/file_manager/file_manager/common/js/util.js

@@ -1397,6 +1397,14 @@ util.isFeedbackPanelEnabled = () => {
   return loadTimeData.getBoolean('FEEDBACK_PANEL_ENABLED');
 };
 
+/**
+ * Returns true when FilesNG is enabled.
+ * @return {boolean}
+ */
+util.isFilesNg = () => {
+  return loadTimeData.getBoolean('FILES_NG_ENABLED');
+};
+
 /**
  * Retrieves all entries inside the given |rootEntry|.
  * @param {!DirectoryEntry} rootEntry

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

@@ -757,6 +757,9 @@ class FileManager extends cr.EventTarget {
     metrics.recordInterval('Load.InitDocuments');
 
     metrics.startInterval('Load.InitUI');
+    if (util.isFilesNg()) {
+      this.dialogDom_.classList.add('files-ng');
+    }
     this.initEssentialUI_();
     this.initAdditionalUI_();
     await this.initSettingsPromise_;