Reland support flutter test on platform chrome (#33859)

diff --git a/packages/flutter_tools/lib/src/web/compile.dart b/packages/flutter_tools/lib/src/web/compile.dart
index e987498..732769a 100644
--- a/packages/flutter_tools/lib/src/web/compile.dart
+++ b/packages/flutter_tools/lib/src/web/compile.dart
@@ -91,7 +91,8 @@
   /// `projectDirectory`.
   Future<void> initialize({
     @required Directory projectDirectory,
-    @required String target,
+    @required List<String> targets,
+    String testOutputDir,
   }) async {
     throw UnimplementedError();
   }