[filesapp] Update html.pointer-active on transfer end events

Terminal events of transferController operations (drag-end, touch-end)
should also remove pointer-active from the html element.

Bug: 1062902
Change-Id: I5da0d327b170bf6128ef5b554a692ba9490cdd58
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2127166Reviewed-by: Alex Danilo <adanilo@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#754741}

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

@@ -433,11 +433,12 @@ class FileManagerUI {
     document.defaultView.addEventListener('resize', this.relayout.bind(this));
 
     // Add global pointer-active handler.
-    const pointerActiveEvents = window.IN_TEST ?
-        ['pointerdown', 'pointerup', 'mousedown', 'mouseup'] :
-        ['pointerdown', 'pointerup'];
     const rootElement = document.documentElement;
-    pointerActiveEvents.forEach((eventType) => {
+    let pointerActive = ['pointerdown', 'pointerup', 'dragend', 'touchend'];
+    if (window.IN_TEST) {
+      pointerActive = pointerActive.concat(['mousedown', 'mouseup']);
+    }
+    pointerActive.forEach((eventType) => {
       document.addEventListener(eventType, (e) => {
         rootElement.classList.toggle('pointer-active', /down$/.test(e.type));
       }, true);