Video player: Generate JS modules for video player background deps

JS Modules for the following files in ui/file_manger/video_player/js:
- background.js
- error_util.js
- test_util.js

Add the main_background.m.js to act as the entry point for the
background page.

Bug: 1133186
Change-Id: I0c1a205047c85f70e4629d5a3f52ddfcfcbedd7c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2596467
Commit-Queue: Jeremie Boulic <jboulic@chromium.org>
Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837950}

ui/file_manager/video_player/js/BUILD.gn

@@ -7,9 +7,21 @@ import("//third_party/closure_compiler/js_unit_tests.gni")
 import("//ui/file_manager/base/gn/js_test_gen_html.gni")
 import("//ui/webui/resources/tools/js_modulizer.gni")
 
+group("closure_compile") {
+  testonly = true
+  deps = [
+    ":closure_compile_jsmodules",
+    ":closure_compile_module",
+    ":js_test_gen_html_modules_type_check_auto",
+  ]
+}
+
 js_type_check("closure_compile_jsmodules") {
   uses_js_modules = true
   deps = [
+    ":background.m",
+    ":error_util.m",
+    ":test_util.m",
     ":video_player_metrics.m",
     ":video_player_native_controls.m",
   ]
@@ -46,9 +58,41 @@ js_library("background") {
   ]
 }
 
+js_library("background.m") {
+  sources = [ "$root_gen_dir/ui/file_manager/video_player/js/background.m.js" ]
+  deps = [
+    "//ui/file_manager/externs/background:background_base.m",
+    "//ui/file_manager/file_manager/background/js:app_window_wrapper.m",
+    "//ui/file_manager/file_manager/background/js:background_base.m",
+    "//ui/file_manager/file_manager/common/js:util.m",
+    "//ui/webui/resources/js:assert.m",
+  ]
+
+  extra_deps = [ ":modulize" ]
+}
+
 js_library("error_util") {
 }
 
+js_library("error_util.m") {
+  sources = [ "$root_gen_dir/ui/file_manager/video_player/js/error_util.m.js" ]
+
+  extra_deps = [ ":modulize" ]
+}
+
+js_library("test_util") {
+}
+
+js_library("test_util.m") {
+  sources = [ "$root_gen_dir/ui/file_manager/video_player/js/test_util.m.js" ]
+  deps = [
+    ":background.m",
+    "//ui/file_manager/file_manager/background/js:test_util_base.m",
+  ]
+
+  extra_deps = [ ":modulize" ]
+}
+
 js_library("video_player_native_controls") {
   deps = [
     "//ui/file_manager/base/js:app_util",
@@ -121,12 +165,12 @@ js_test_gen_html("js_test_gen_html_modules") {
       ]
 }
 
-group("closure_compile") {
-  testonly = true
+js_library("main_background.m") {
   deps = [
-    ":closure_compile_jsmodules",
-    ":closure_compile_module",
-    ":js_test_gen_html_modules_type_check_auto",
+    ":background.m",
+    ":error_util.m",
+    ":test_util.m",
+    ":video_player_metrics.m",
   ]
 }
 
@@ -134,5 +178,8 @@ js_modulizer("modulize") {
   input_files = [
     "video_player_native_controls.js",
     "video_player_metrics.js",
+    "error_util.js",
+    "test_util.js",
+    "background.js",
   ]
 }

ui/file_manager/video_player/js/background.js

@@ -2,6 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// clang-format off
+// #import {assert} from 'chrome://resources/js/assert.m.js';
+// #import {AppWindowWrapper} from '../../file_manager/background/js/app_window_wrapper.m.js';
+// #import {util} from '../../file_manager/common/js/util.m.js';
+// #import {BackgroundBaseImpl} from '../../file_manager/background/js/background_base.m.js';
+// #import {BackgroundBase} from '../../externs/background/background_base.m.js';
+// clang-format on
+
 /**
  * Use maximum size and let ash downsample the icon.
  *
@@ -47,7 +55,7 @@ const generateWindowId = (function() {
  *     playing.
  * @return {!Promise} Promise to be fulfilled on success, or rejected on error.
  */
-function openVideoPlayerWindow(urls) {
+/* #export */ function openVideoPlayerWindow(urls) {
   let position = 0;
   const startUrl = (position < urls.length) ? urls[position] : '';
   let windowId = null;

ui/file_manager/video_player/js/main_background.m.js

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @fileoverview Entry point for it replaces background_scripts.js.
+ */
+
+import './error_util.m.js';
+import './test_util.m.js';
+import './video_player_metrics.m.js';
+import './background.m.js';

ui/file_manager/video_player/js/test_util.js

@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// #import {openVideoPlayerWindow} from './background.m.js';
+// #import {test} from '../../file_manager/background/js/test_util_base.m.js';
+
 /**
  * Returns if a video element playing the specified file meet the condition
  * which is given by a parameter.
@@ -10,11 +13,11 @@
  * @param {function(!Element):boolean} testFunction
  */
 function testElement(filename, testFunction) {
-  for (var appId in window.appWindows) {
-    var contentWindow = window.appWindows[appId].contentWindow;
+  for (const appId in window.appWindows) {
+    const contentWindow = window.appWindows[appId].contentWindow;
     if (contentWindow &&
         contentWindow.document.title === filename) {
-      var element = contentWindow.document.querySelector('video');
+      const element = contentWindow.document.querySelector('video');
       if (element && testFunction(element)) {
         return true;
       }
@@ -62,7 +65,7 @@ test.util.sync.hasSubtitle = function(filename) {
  * @param {Window} contentWindow Video player window to be chacked toOB.
  */
 test.util.sync.loadMockCastExtension = function(contentWindow) {
-  var script = contentWindow.document.createElement('script');
+  const script = contentWindow.document.createElement('script');
   script.src =
       'chrome-extension://ljoplibgfehghmibaoaepfagnmbbfiga/' +
       'cast_extension_mock/load.js';