Hot restart is broken when running DWDS without Chrome Debug Port

[nshahan]

Hot restart crashes when running with with WIP change to support DWDS without a Chrome Debug Port #2639.

Repro:

1. Patching those changes and update flutter_tools accordingly.
2. Run the app flutter run -d web-server.
3. Open in a browser and wait for it to load.
4. Save an edit to the application source code.
5. In the terminal press “shift-r” to Hot Restart the app.

$ flutter run -d web-server
Launching lib/main.dart on Web Server in debug mode...
Waiting for connection from debug service on Web Server...          8.5s
lib/main.dart is being served at http://localhost:55483
The web-server device requires the Dart Debug Chrome extension for debugging. Consider using
the Chrome or Edge devices for an improved development workflow.
Debug service listening on ws://127.0.0.1:55501/7-vJ9RnUtmw=

Flutter run key commands.
r Hot reload. 🔥🔥🔥
R Hot restart.
h List all available interactive commands.
d Detach (terminate "flutter run" but leave application running).
c Clear the screen
q Quit (terminate the application on the device).

A Dart VM Service on Web Server is available at: http://127.0.0.1:55501/7-vJ9RnUt

Performing hot restart...                                           37ms
hotRestart: (-32601) Method not found

Related issue: #2605

Note: this is broken when app is ran from both Vscode and CMD line