[flutter_tool] fix NPE in daemon caused by returning null connection info from...

[flutter_tool] fix NPE in daemon caused by returning null connection info from experimental web runner (#46909)

packages/flutter_tools/lib/src/build_runner/resident_web_runner.dart

@@ -535,7 +535,7 @@ class _ExperimentalResidentWebRunner extends ResidentWebRunner {
       _wipConnection = await chromeTab.connect();
     }
     appStartedCompleter?.complete();
-    connectionInfoCompleter?.complete();
+    connectionInfoCompleter?.complete(DebugConnectionInfo());
     if (stayResident) {
       await waitForAppToFinish();
     } else {

packages/flutter_tools/test/general.shard/resident_web_runner_test.dart

@@ -378,7 +378,10 @@ void main() {
     unawaited(residentWebRunner.run(
       connectionInfoCompleter: connectionInfoCompleter,
     ));
-    await connectionInfoCompleter.future;
+    final DebugConnectionInfo debugConnectionInfo = await connectionInfoCompleter.future;
+
+    expect(debugConnectionInfo, isNotNull);
+
     final OperationResult result = await residentWebRunner.restart(fullRestart: false);
 
     expect(testLogger.statusText, contains('Reloaded application in'));