Move the various DOM-factories into their own files

 - Over time the number and size of these factories have increased, especially the `DOMFilterFactory` class, and this split should thus aid readability/maintainability of the code.

 - By introducing a couple of new import maps we can avoid bundling the `DOMCMapReaderFactory`/`DOMStandardFontDataFactory` classes in the Firefox PDF Viewer, since they are dead code there given that worker-thread fetching is always being used.

 - This patch has been successfully tested, by running `$ ./mach test toolkit/components/pdfjs/`, in a local Firefox artifact-build.

*Note:* This patch reduces the size of the `gulp mozcentral` output by `1.3` kilo-bytes, which isn't a lot but still cannot hurt.

gulpfile.mjs

@@ -191,6 +191,8 @@ function createWebpackAlias(defines) {
     "fluent-dom": "node_modules/@fluent/dom/esm/index.js",
   };
   const libraryAlias = {
+    "display-cmap_reader_factory": "src/display/stubs.js",
+    "display-standard_fontdata_factory": "src/display/stubs.js",
     "display-fetch_stream": "src/display/stubs.js",
     "display-network": "src/display/stubs.js",
     "display-node_stream": "src/display/stubs.js",
@@ -219,6 +221,10 @@ function createWebpackAlias(defines) {
   };
 
   if (defines.CHROME) {
+    libraryAlias["display-cmap_reader_factory"] =
+      "src/display/cmap_reader_factory.js";
+    libraryAlias["display-standard_fontdata_factory"] =
+      "src/display/standard_fontdata_factory.js";
     libraryAlias["display-fetch_stream"] = "src/display/fetch_stream.js";
     libraryAlias["display-network"] = "src/display/network.js";
 
@@ -231,6 +237,10 @@ function createWebpackAlias(defines) {
     // Aliases defined here must also be replicated in the paths section of
     // the tsconfig.json file for the type generation to work.
     // In the tsconfig.json files, the .js extension must be omitted.
+    libraryAlias["display-cmap_reader_factory"] =
+      "src/display/cmap_reader_factory.js";
+    libraryAlias["display-standard_fontdata_factory"] =
+      "src/display/standard_fontdata_factory.js";
     libraryAlias["display-fetch_stream"] = "src/display/fetch_stream.js";
     libraryAlias["display-network"] = "src/display/network.js";
     libraryAlias["display-node_stream"] = "src/display/node_stream.js";
@@ -1573,6 +1583,8 @@ function buildLibHelper(bundleDefines, inputStream, outputDir) {
     defines: bundleDefines,
     map: {
       "pdfjs-lib": "../pdf.js",
+      "display-cmap_reader_factory": "./cmap_reader_factory.js",
+      "display-standard_fontdata_factory": "./standard_fontdata_factory.js",
       "display-fetch_stream": "./fetch_stream.js",
       "display-network": "./network.js",
       "display-node_stream": "./node_stream.js",

src/display/annotation_layer.js

@@ -37,13 +37,10 @@ import {
   Util,
   warn,
 } from "../shared/util.js";
-import {
-  DOMSVGFactory,
-  PDFDateString,
-  setLayerDimensions,
-} from "./display_utils.js";
+import { PDFDateString, setLayerDimensions } from "./display_utils.js";
 import { AnnotationStorage } from "./annotation_storage.js";
 import { ColorConverters } from "../shared/scripting_utils.js";
+import { DOMSVGFactory } from "./svg_factory.js";
 import { XfaLayer } from "./xfa_layer.js";
 
 const DEFAULT_TAB_INDEX = 1000;

src/display/api.js

@@ -45,10 +45,6 @@ import {
 } from "./annotation_storage.js";
 import {
   deprecated,
-  DOMCanvasFactory,
-  DOMCMapReaderFactory,
-  DOMFilterFactory,
-  DOMStandardFontDataFactory,
   isDataScheme,
   isValidFetchUrl,
   PageViewport,
@@ -64,6 +60,10 @@ import {
   NodeStandardFontDataFactory,
 } from "display-node_utils";
 import { CanvasGraphics } from "./canvas.js";
+import { DOMCanvasFactory } from "./canvas_factory.js";
+import { DOMCMapReaderFactory } from "display-cmap_reader_factory";
+import { DOMFilterFactory } from "./filter_factory.js";
+import { DOMStandardFontDataFactory } from "display-standard_fontdata_factory";
 import { GlobalWorkerOptions } from "./worker_options.js";
 import { MessageHandler } from "../shared/message_handler.js";
 import { Metadata } from "./metadata.js";