Allow skipping webOnlyInitializePlatform in Flutter for Web (#40301)

diff --git a/packages/flutter_tools/lib/src/web/compile.dart b/packages/flutter_tools/lib/src/web/compile.dart
index f749851..e40a37d 100644
--- a/packages/flutter_tools/lib/src/web/compile.dart
+++ b/packages/flutter_tools/lib/src/web/compile.dart
@@ -18,7 +18,7 @@
 /// The [WebCompilationProxy] instance.
 WebCompilationProxy get webCompilationProxy => context.get<WebCompilationProxy>();
 
-Future<void> buildWeb(FlutterProject flutterProject, String target, BuildInfo buildInfo) async {
+Future<void> buildWeb(FlutterProject flutterProject, String target, BuildInfo buildInfo, bool initializePlatform) async {
   if (!flutterProject.web.existsSync()) {
     throwToolExit('Missing index.html.');
   }
@@ -32,6 +32,7 @@
       projectDirectory: FlutterProject.current().directory,
       mode: buildInfo.mode,
       projectName: flutterProject.manifest.appName,
+      initializePlatform: initializePlatform,
     );
     if (result) {
       // Places assets adjacent to the web stuff.
@@ -84,6 +85,7 @@
     @required String projectName,
     String testOutputDir,
     BuildMode mode,
+    bool initializePlatform,
   }) async {
     throw UnimplementedError();
   }