[dart2wasm] Migrate our embedders to new mjs API

To test that the deprecated mjs API functions still work we landed the
new mjs API in [0] seperately.

This CL then migrates our 2 different users of the mjs api
in the Dart SDK (for testing and benchmarking) to the new API.

[0] https://dart-review.googlesource.com/c/sdk/+/383242

Change-Id: Ibbe58c9a977326a8fbff780d328d7f54784bd323
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/382888
Reviewed-by: Ömer Ağacan <omersa@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Nate Biggs <natebiggs@google.com>

pkg/dart2wasm/bin/run_wasm.js

@@ -394,15 +394,13 @@ const main = async () => {
   }
 
   // Instantiate the Dart module, importing from the global scope.
-  const dartInstance = await dart2wasm.instantiate(
-    dart2wasm.compile(readBytes(args[wasmArg])),
-    Promise.resolve(importObject),
-  );
+  const compiledApp = await dart2wasm.compile(readBytes(args[wasmArg]));
+  const appInstance = await compiledApp.instantiate(importObject);
 
   // Call `main`. If tasks are placed into the event loop (by scheduling tasks
   // explicitly or awaiting Futures), these will automatically keep the script
   // alive even after `main` returns.
-  await dart2wasm.invoke(dartInstance, ...dartArgs);
+  await appInstance.invokeMain(...dartArgs);
 };
 
 dartMainRunner(main, []);

pkg/test_runner/lib/src/browser.dart

@@ -328,15 +328,16 @@ String dart2wasmHtml(String title, String wasmPath, String mjsPath) {
           src="/root_dart/pkg/test_runner/lib/src/test_controller.js">
   </script>
   <script type="module">
-  let dart2wasm_runtime = await import('$mjsPath');
-  const dartModulePromise =
-      dart2wasm_runtime.compileStreaming(fetch('$wasmPath'));
-  let moduleInstance =
-      await dart2wasm_runtime.instantiate(dartModulePromise, {});
+  async function loadAndRun(mjsPath, wasmPath) {
+    const mjs = await import(mjsPath);
+    const compiledApp = await mjs.compileStreaming(fetch(wasmPath));
+    const appInstance = await compiledApp.instantiate({});
+    dartMainRunner(() => {
+      appInstance.invokeMain();
+    });
+  }
 
-  dartMainRunner(() => {
-    dart2wasm_runtime.invoke(moduleInstance);
-  });
+  loadAndRun('$mjsPath', '$wasmPath');
   </script>
 </body>
 </html>""";