Default the CanvasKit base URL to local artifacts. (#40293)

Author: Harry Terkelsen

lib/web_ui/README.md

@@ -197,34 +197,6 @@ Resources:
 2. LUCI web [recipe][5]
 3. More general reading on CIPD packages [link][6]
 
-### Rolling CanvasKit
-
-CanvasKit is versioned separately from Skia and rolled manually. Flutter
-consumes a pre-built CanvasKit provided by the Skia team, currently hosted on
-unpkg.com. When a new version of CanvasKit is available (check
-https://www.npmjs.com/package/canvaskit-wasm or consult the Skia team
-directly), follow these steps to roll to the new version:
-
-- Make sure you have `depot_tools` installed (if you are regularly hacking on
-  the engine code, you probably do).
-- If not already authenticated with CIPD, run `cipd auth-login` and follow
-  instructions (this step requires sufficient privileges; file a github
-  infra ticket queue issue: https://github.com/flutter/flutter/wiki/Infra-Ticket-Queue
-  to get access)
-- Edit `dev/canvaskit_lock.yaml` and update the value of `canvaskit_version`
-  to the new version.
-- Run `dart dev/canvaskit_roller.dart` and make sure it completes successfully.
-  The script uploads the new version of CanvasKit to the
-  `flutter/web/canvaskit_bundle` CIPD package, and writes the CIPD package
-  instance ID to the DEPS file.
-- Rerun `gclient sync` and do a clean build to test that the new version is
-  picked up.
-- Send a pull request containing the above file changes. If the new version
-  contains breaking changes, the PR must also contain corresponding fixes.
-
-If you have questions, contact the Flutter Web team on Flutter Discord on the
-#hackers-web-🌍 channel.
-
 ### Rolling Noto Font Data
 
 In order to generate new data for the Noto fallback fonts, you will need

lib/web_ui/dev/canvaskit_lock.yaml

@@ -49,11 +49,6 @@ import 'package:meta/meta.dart';
 import 'canvaskit/renderer.dart';
 import 'dom.dart';
 
-/// The version of CanvasKit used by the web engine by default.
-// DO NOT EDIT THE NEXT LINE OF CODE MANUALLY
-// See `lib/web_ui/README.md` for how to roll CanvasKit to a new version.
-const String _canvaskitVersion = '0.38.0';
-
 /// The Web Engine configuration for the current application.
 FlutterConfiguration get configuration =>
   _configuration ??= FlutterConfiguration.legacy(_jsConfiguration);
@@ -182,7 +177,7 @@ class FlutterConfiguration {
   String get canvasKitBaseUrl => _configuration?.canvasKitBaseUrl ?? _defaultCanvasKitBaseUrl;
   static const String _defaultCanvasKitBaseUrl = String.fromEnvironment(
     'FLUTTER_WEB_CANVASKIT_URL',
-    defaultValue: 'https://unpkg.com/canvaskit-wasm@$_canvaskitVersion/bin/',
+    defaultValue: 'canvaskit/',
   );
 
   /// The variant of CanvasKit to download.