Remove the createPreferences method from DefaultExternalServices

Given the simplicity of the `createPreferences` method, we can leverage import maps to directly initialize the correct `Preferences`-instance depending on the build.

web/app.js

@@ -73,6 +73,7 @@ import { PDFScriptingManager } from "./pdf_scripting_manager.js";
 import { PDFSidebar } from "web-pdf_sidebar";
 import { PDFThumbnailViewer } from "web-pdf_thumbnail_viewer";
 import { PDFViewer } from "./pdf_viewer.js";
+import { Preferences } from "web-preferences";
 import { SecondaryToolbar } from "web-secondary_toolbar";
 import { Toolbar } from "web-toolbar";
 import { ViewHistory } from "./view_history.js";
@@ -99,10 +100,6 @@ class DefaultExternalServices {
 
   static reportTelemetry(data) {}
 
-  static createPreferences() {
-    throw new Error("Not implemented: createPreferences");
-  }
-
   static async createL10n() {
     throw new Error("Not implemented: createL10n");
   }
@@ -617,7 +614,7 @@ const PDFViewerApplication = {
   },
 
   async run(config) {
-    this.preferences = this.externalServices.createPreferences();
+    this.preferences = new Preferences();
     await this.initialize(config);
 
     const { appConfig, eventBus } = this;

web/chromecom.js

@@ -325,7 +325,7 @@ function setReferer(url, callback) {
 // chrome.storage.local to chrome.storage.sync when needed.
 const storageArea = chrome.storage.sync || chrome.storage.local;
 
-class ChromePreferences extends BasePreferences {
+class Preferences extends BasePreferences {
   async _writeToStorage(prefObj) {
     return new Promise(resolve => {
       if (prefObj === this.defaults) {
@@ -426,10 +426,6 @@ class ChromeExternalServices extends DefaultExternalServices {
     );
   }
 
-  static createPreferences() {
-    return new ChromePreferences();
-  }
-
   static async createL10n() {
     return new GenericL10n(navigator.language);
   }
@@ -440,4 +436,4 @@ class ChromeExternalServices extends DefaultExternalServices {
 }
 PDFViewerApplication.externalServices = ChromeExternalServices;
 
-export { ChromeCom };
+export { ChromeCom, Preferences };

web/firefoxcom.js

@@ -147,7 +147,7 @@ class DownloadManager {
   }
 }
 
-class FirefoxPreferences extends BasePreferences {
+class Preferences extends BasePreferences {
   async _readFromStorage(prefObj) {
     return FirefoxCom.requestAsync("getPreferences", prefObj);
   }
@@ -382,10 +382,6 @@ class FirefoxExternalServices extends DefaultExternalServices {
     FirefoxCom.request("reportTelemetry", JSON.stringify(data));
   }
 
-  static createPreferences() {
-    return new FirefoxPreferences();
-  }
-
   static updateEditorStates(data) {
     FirefoxCom.request("updateEditorStates", data);
   }
@@ -412,4 +408,4 @@ class FirefoxExternalServices extends DefaultExternalServices {
 }
 PDFViewerApplication.externalServices = FirefoxExternalServices;
 
-export { DownloadManager, FirefoxCom };
+export { DownloadManager, FirefoxCom, Preferences };

web/genericcom.js

@@ -27,7 +27,7 @@ if (typeof PDFJSDev !== "undefined" && !PDFJSDev.test("GENERIC")) {
 
 const GenericCom = {};
 
-class GenericPreferences extends BasePreferences {
+class Preferences extends BasePreferences {
   async _writeToStorage(prefObj) {
     localStorage.setItem("pdfjs.preferences", JSON.stringify(prefObj));
   }
@@ -38,10 +38,6 @@ class GenericPreferences extends BasePreferences {
 }
 
 class GenericExternalServices extends DefaultExternalServices {
-  static createPreferences() {
-    return new GenericPreferences();
-  }
-
   static async createL10n() {
     return new GenericL10n(AppOptions.get("locale"));
   }
@@ -52,4 +48,4 @@ class GenericExternalServices extends DefaultExternalServices {
 }
 PDFViewerApplication.externalServices = GenericExternalServices;
 
-export { GenericCom };
+export { GenericCom, Preferences };

web/viewer-geckoview.html

@@ -72,6 +72,7 @@ See https://github.com/adobe-type-tools/cmap-resources
           "web-pdf_presentation_mode": "./stubs-geckoview.js",
           "web-pdf_sidebar": "./stubs-geckoview.js",
           "web-pdf_thumbnail_viewer": "./stubs-geckoview.js",
+          "web-preferences": "./genericcom.js",
           "web-print_service": "./pdf_print_service.js",
           "web-secondary_toolbar": "./stubs-geckoview.js",
           "web-toolbar": "./toolbar-geckoview.js"

web/viewer.html

@@ -81,6 +81,7 @@ See https://github.com/adobe-type-tools/cmap-resources
           "web-pdf_presentation_mode": "./pdf_presentation_mode.js",
           "web-pdf_sidebar": "./pdf_sidebar.js",
           "web-pdf_thumbnail_viewer": "./pdf_thumbnail_viewer.js",
+          "web-preferences": "./genericcom.js",
           "web-print_service": "./pdf_print_service.js",
           "web-secondary_toolbar": "./secondary_toolbar.js",
           "web-toolbar": "./toolbar.js"