Restrict access to FilesApp background object

Contain all FilesApp foreground access to the background
object to the FileManager class.

This simplifies a lot of the externs dependencies and
I think it provides a cleaner API.

Change-Id: I96716d0c53d538a90adfb04f9f54ce6cd7d72568
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1761880Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Auto-Submit: Joel Hockey <joelhockey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#688460}

ui/file_manager/externs/command_handler_deps.js

@@ -11,9 +11,6 @@ class CommandHandlerDeps {
     /** @type {ActionsController} */
     this.actionsController;
 
-    /** @type {BackgroundWindow} */
-    this.backgroundPage;
-
     /** @type {DialogType} */
     this.dialogType;
 
@@ -71,4 +68,7 @@ class CommandHandlerDeps {
 
   /** @return {FileSelection} */
   getSelection() {}
+
+  /** @param {Object} appState App state. */
+  launchFileManager(appState) {}
 }

ui/file_manager/file_manager/common/js/BUILD.gn

@@ -86,10 +86,6 @@ js_library("importer_common") {
     "../../../externs:volume_manager",
     "//ui/file_manager/base/js:volume_manager_types",
   ]
-  externs_list = [
-    "../../../externs/background_window.js",
-    "../../../externs/background/file_browser_background.js",
-  ]
 }
 
 js_library("test_importer_common") {

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

@@ -437,13 +437,6 @@ class FileManager extends cr.EventTarget {
     return this.fileOperationManager_;
   }
 
-  /**
-   * @return {BackgroundWindow}
-   */
-  get backgroundPage() {
-    return this.backgroundPage_;
-  }
-
   /**
    * @return {FilteredVolumeManager}
    */
@@ -486,6 +479,14 @@ class FileManager extends cr.EventTarget {
     return this.ui_;
   }
 
+  /**
+   * Launch a new File Manager app.
+   * @param {Object=} appState App state.
+   */
+  launchFileManager(appState) {
+    this.backgroundPage_.launcher.launchFileManager(appState);
+  }
+
   /**
    * One time initialization for app state controller to load view option from
    * local storage.

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

@@ -862,7 +862,7 @@ CommandHandler.COMMANDS_['new-folder'] = new class extends Command {
  */
 CommandHandler.COMMANDS_['new-window'] = new class extends Command {
   execute(event, fileManager) {
-    fileManager.backgroundPage.launcher.launchFileManager({
+    fileManager.launchFileManager({
       currentDirectoryURL: fileManager.getCurrentDirectoryEntry() &&
           fileManager.getCurrentDirectoryEntry().toURL()
     });

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

@@ -1240,9 +1240,8 @@ importer.RuntimeControllerEnvironment = class {
    * @private
    */
   revealDirectory_(directory) {
-    this.fileManager_.backgroundPage.launcher.launchFileManager(
-        {currentDirectoryURL: directory.toURL()},
-        /* App ID */ undefined);
+    this.fileManager_.launchFileManager(
+        {currentDirectoryURL: directory.toURL()});
   }
 
   /**