Waiting for connection from Dart debug extension

Hi guys.
Launching example app from VSCode it not works.
Google Chrome with Dart Debug Extension installed shows blank page.
Thanks a lot for support.
```
Dart Code extension: 3.11.0
Flutter extension: 3.11.0 (not activated)

App: Visual Studio Code
Remote: wsl
Version: 1.46.0
Platform: linux

Workspace type: Flutter
Multi-root?: false

Dart SDK:
Loc: /opt/flutter/bin/cache/dart-sdk
Ver: 2.9.0-8.2.beta
Flutter SDK:
Loc: /opt/flutter
Ver: 1.18.0-11.1.pre

HTTP_PROXY: undefined
NO_PROXY: undefined

Thu Jun 11 2020 [08:43:57 GMT+0200 (Central European Summer Time)] Log file started
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] Termination requested!
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Requested to terminate with SIGINT...
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Terminating processes...
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Terminating related process 1076 with SIGINT...
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Terminating main process with SIGINT...
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Disabling break-on-exception and removing all breakpoints
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Unpausing all threads...
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Removing all stored data...
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Waiting for process to finish...
[8:44:10 AM] [FlutterRun] [Info] [Flutter (Web Server)] Process terminated! null, SIGINT
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] Process exited (sigint)
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Disconnecting...
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] Disconnect requested!
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Requested to terminate with SIGINT...
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Did not need to terminate processes
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Removing all stored data...
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Waiting for process to finish...
[8:44:10 AM] [Observatory] [Info] [Flutter (Web Server)] TERM: Disconnecting...
[8:44:11 AM] [General] [Info] Debugger:SessionDuration timing: 182153ms (Flutter)
[8:44:12 AM] [General] [Info] Starting debug session...
[8:44:12 AM] [General] [Info] workspace: /home/fcioffi/coding/myapp
[8:44:12 AM] [General] [Info] Using found common entry point: /home/fcioffi/coding/myapp/lib/main.dart
[8:44:12 AM] [General] [Info] Using workspace as cwd: /home/fcioffi/coding/myapp
[8:44:12 AM] [General] [Info] Detected launch project as Flutter
[8:44:12 AM] [General] [Info] Using Flutter debug adapter for this session
[8:44:12 AM] [FlutterDaemon] [Info] ==> [{"id":"6","method":"daemon.getSupportedPlatforms","params":{"projectRoot":"/home/fcioffi/coding/myapp"}}]
[8:44:12 AM] [FlutterDaemon] [Info] <== [{"id":"6","result":{"platforms":["ios","android","web"]}}]
[8:44:12 AM] [General] [Info] Checking for errors before launching
[8:44:12 AM] [General] [Info] Debug session starting...
{
"type": "dart",
"request": "launch",
"program": "/home/fcioffi/coding/myapp/lib/main.dart",
"cwd": "/home/fcioffi/coding/myapp",
"name": "Flutter (Web Server)",
"toolEnv": {
"FLUTTER_HOST": "VSCode",
"PUB_ENVIRONMENT": "vscode.dart-code"
},
"sendLogsToClient": true,
"globalFlutterArgs": [],
"args": [],
"vmAdditionalArgs": [],
"vmServicePort": 0,
"dartPath": "/opt/flutter/bin/cache/dart-sdk/bin/dart",
"maxLogLineLength": 2000,
"pubPath": "/opt/flutter/bin/cache/dart-sdk/bin/pub",
"pubSnapshotPath": "/opt/flutter/bin/cache/dart-sdk/bin/snapshots/pub.dart.snapshot",
"debugSdkLibraries": false,
"debugExternalLibraries": false,
"showDartDeveloperLogs": true,
"useFlutterStructuredErrors": true,
"debuggerHandlesPathsEverywhereForBreakpoints": true,
"supportsWsVmService": true,
"supportsExposeUrl": true,
"evaluateGettersInDebugViews": true,
"evaluateToStringInDebugViews": true,
"useWriteServiceInfo": true,
"supportsDebugInternalLibraries": false,
"forceFlutterVerboseMode": true,
"flutterTrackWidgetCreation": true,
"flutterMode": "debug",
"flutterPlatform": "default",
"flutterPath": "/opt/flutter/bin/flutter",
"deviceId": "web-server",
"deviceName": "Web Server (web-javascript)",
"showMemoryUsage": false,
"debugServer": 51156,
"debuggerType": 2
}
[8:44:12 AM] [FlutterRun] [Info] [Flutter (Web Server)] Spawning /opt/flutter/bin/flutter with args ["run","--machine","--target","lib/main.dart","-d","web-server","--track-widget-creation","--start-paused","--web-server-debug-protocol","ws","--web-allow-expose-url","-v"]
[8:44:12 AM] [FlutterRun] [Info] [Flutter (Web Server)] .. in /home/fcioffi/coding/myapp
[8:44:12 AM] [FlutterRun] [Info] [Flutter (Web Server)] .. with {"toolEnv":{"FLUTTER_HOST":"VSCode","PUB_ENVIRONMENT":"vscode.dart-code"}}
[8:44:12 AM] [FlutterRun] [Info] [Flutter (Web Server)] PID: 647
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +11 ms] executing: [/opt/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +53 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] 2738a1148ba6c9a6114df62358109407c3ef2553
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] executing: [/opt/flutter/] git tag --contains HEAD
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +184 ms] Exit code 0 from: git tag --contains HEAD
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +1 ms] 1.18.0-11.1.pre
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +9 ms] executing: [/opt/flutter/] git rev-parse --abbrev-ref --symbolic @{u}
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +17 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +1 ms] origin/beta
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] executing: [/opt/flutter/] git ls-remote --get-url origin
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +17 ms] Exit code 0 from: git ls-remote --get-url origin
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +1 ms] https://github.com/flutter/flutter.git
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +114 ms] executing: [/opt/flutter/] git rev-parse --abbrev-ref HEAD
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +24 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +1 ms] beta
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +46 ms] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +2 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +16 ms] executing: /opt/Android/platform-tools/adb devices -l
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +81 ms] List of devices attached
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +7 ms] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +2 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +234 ms] Generating /home/fcioffi/coding/myapp/android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegistrant.java
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [{"event":"daemon.connected","params":{"version":"0.5.3","pid":1172}}]
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [{"event":"app.start","params":{"appId":"d2219151-917a-4597-9c1a-dd9632f18e0f","deviceId":"web-server","directory":"/home/fcioffi/coding/myapp","supportsRestart":true,"launchMode":"run"}}]
[8:44:13 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +101 ms] Launching lib/main.dart on Web Server in debug mode...
[8:44:14 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [{"method":"app.exposeUrl","params":{"url":"http://127.0.0.1:51855/$debug"},"id":"1"}]
[8:44:14 AM] [General] [Info] Exposing URL: http://127.0.0.1:51855/%24debug
[8:44:14 AM] [General] [Info] Mapping URL: http://127.0.0.1:51855/%24debug
[8:44:14 AM] [General] [Info] Mapped URL: http://127.0.0.1:51856/%24debug
[8:44:14 AM] [General] [Info] Final URI: http://127.0.0.1:51856/$debug
[8:44:14 AM] [General] [Info] Final URL: http://127.0.0.1:51856/$debug
[8:44:14 AM] [FlutterRun] [Info] [Flutter (Web Server)] ==> [{"id":"1","result":{"url":"http://127.0.0.1:51856/$debug"}}]
[8:44:14 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +77 ms] Updating assets
[8:44:14 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [{"event":"app.progress","params":{"appId":"d2219151-917a-4597-9c1a-dd9632f18e0f","id":"0","progressId":null,"message":"Syncing files to device Web Server..."}}]
[8:44:14 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +135 ms] Generating /home/fcioffi/coding/myapp/android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegistrant.java
[8:44:14 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +35 ms] <- reset
[8:44:14 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +6 ms] /opt/flutter/bin/cache/dart-sdk/bin/dart /opt/flutter/bin/cache/artifacts/engine/linux-x64/frontend_server.dart.snapshot --sdk-root /opt/flutter/bin/cache/flutter_web_sdk/ --incremental --target=dartdevc --debugger-module-names -Ddart.developer.causal_async_stacks=true --output-dill /tmp/flutter_tool.XOMDOZ/app.dill --libraries-spec file:///opt/flutter/bin/cache/flutter_web_sdk/libraries.json --packages .packages -Ddart.vm.profile=false -Ddart.vm.product=false --bytecode-options=source-positions,local-var-info,debugger-stops,instance-field-initializers,keep-unreachable-code,avoid-closure-call-instructions --enable-asserts --track-widget-creation --filesystem-root /tmp/flutter_tools.ZSBGVO --filesystem-scheme org-dartlang-app --initialize-from-dill build/cache.dill --platform file:///opt/flutter/bin/cache/flutter_web_sdk/kernel/flutter_ddc_sdk.dill
[8:44:14 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +26 ms] <- compile org-dartlang-app:/web_entrypoint.dart
[8:44:15 AM] [Analyzer] [Info] ==> {"id":"35","method":"analysis.getHover","params":{"file":"/home/fcioffi/coding/myapp/lib/main.dart","offset":1329},"clientRequestTime":1591857855878}
[8:44:15 AM] [Analyzer] [Info] <== {"id":"35","result":{"hovers":[{"offset":1329,"length":3,"dartdoc":"Initializes [key] for subclasses.","elementDescription":"{Key key}","elementKind":"parameter","isDeprecated":false,"staticType":"Key"}]}}
[8:44:27 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [{"event":"app.progress","params":{"appId":"d2219151-917a-4597-9c1a-dd9632f18e0f","id":"0","progressId":null,"finished":true}}]
[8:44:27 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [+13242 ms] Synced 22.0MB.
[8:44:27 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ ] <- accept
[8:44:27 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [ +2 ms] Waiting for connection from Dart debug extension at http://localhost:51853
[8:44:27 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [{"event":"app.webLaunchUrl","params":{"url":"http://localhost:51853","launched":false}}]
[8:44:27 AM] [FlutterRun] [Info] [Flutter (Web Server)] <== [{"method":"app.exposeUrl","params":{"url":"http://127.0.0.1:51854"},"id":"2"}]
[8:44:27 AM] [General] [Info] Exposing URL: http://127.0.0.1:51854/
[8:44:27 AM] [General] [Info] Mapping URL: http://127.0.0.1:51854/
[8:44:27 AM] [General] [Info] Mapped URL: http://127.0.0.1:51876/
[8:44:27 AM] [General] [Info] Final URI: http://127.0.0.1:51876/
[8:44:27 AM] [General] [Info] Final URL: http://127.0.0.1:51876/
[8:44:27 AM] [FlutterRun] [Info] [Flutter (Web Server)] ==> [{"id":"2","result":{"url":"http://127.0.0.1:51876/"}}]
[8:46:16 AM] [Analyzer] [Info] ==> {"id":"36","method":"analysis.setPriorityFiles","params":{"files":[]},"clientRequestTime":1591857976433}
[8:46:16 AM] [Analyzer] [Info] <== {"id":"36"}
Thu Jun 11 2020 [08:46:42 GMT+0200 (Central European Summer Time)] Log file ended

```

Start by reproducing the VS Code remote WSL launch with the Flutter web-server device and inspect the debug log around the app.exposeUrl event and the reported blank Chrome page. Compare the Dart debug extension connection with the emitted web-server URL; done means the example app loads and the extension establishes its debug connection without terminating the session.

Written by the indexing model from the issue text.