I was wondering if WebGL is considered stable enough to be enabled by default. It makes some PDFs render much faster and it has been off by default for a while now, so we have had quite some time to test it.

If we decide to enable WebGL by default, we should not forget to update https://github.com/mozilla/pdf.js/blob/master/extensions/chromium/preferences_schema.json#L39 as well.

/cc @yurydelendik 
/cc @Snuffleupagus (because IIRC you were testing WebGL too)

import { viewerCompatibilityParams } from "./viewer_compatibility.js";
import { ViewHistory } from "./view_history.js";
const DEFAULT_SCALE_DELTA = 1.1;
const DISABLE_AUTO_FETCH_LOADING_BAR_TIMEOUT = 5000; 
const FORCE_PAGES_LOADED_TIMEOUT = 10000; 
const WHEEL_ZOOM_DISABLED_TIMEOUT = 1000; 
const ENABLE_PERMISSIONS_CLASS = "enablePermissions";
const ViewOnLoad = {
  UNKNOWN: -1,
  PREVIOUS: 0, 
  INITIAL: 1,
};
const ViewerCssTheme = {
  AUTOMATIC: 0, 
  LIGHT: 1,
  DARK: 2,
};
const KNOWN_VERSIONS = [
  "1.0",
  "1.1",
  "1.2",
  "1.3",
  "1.4",
  "1.5",
  "1.6",
  "1.7",
  "1.8",
  "1.9",
  "2.0",
  "2.1",