[wasm] Add an explicit Abort to wasm streaming builder.

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Iae6942cf2b223a296dda479af26a978576d0c58a
Reviewed-on: https://chromium-review.googlesource.com/584367Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Mircea Trofin <mtrofin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46882}

include/v8.h

@@ -4169,11 +4169,7 @@ class V8_EXPORT WasmModuleObjectBuilderStreaming final {
   // The buffer passed into OnBytesReceived is owned by the caller.
   void OnBytesReceived(const uint8_t*, size_t size);
   void Finish();
-  // Currently, we don't need an explicit Abort, because there's no
-  // activity happening until Finish is called. Should the connection
-  // be dropped, for example, the network layer is expected to reject
-  // the promise and then this object is destroyed, which, at the moment,
-  // just means the {received_buffers_} are freed.
+  void Abort(Local<Value> exception);
 
  private:
   typedef std::pair<std::unique_ptr<const uint8_t[]>, size_t> Buffer;

src/api.cc

@@ -7846,6 +7846,16 @@ void WasmModuleObjectBuilderStreaming::Finish() {
                         {wire_bytes.get(), wire_bytes.get() + total_size_});
 }
 
+void WasmModuleObjectBuilderStreaming::Abort(Local<Value> exception) {
+  Local<Promise::Resolver> resolver =
+      promise_.Get(isolate_).As<Promise::Resolver>();
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate_);
+  i::HandleScope scope(i_isolate);
+  Local<Context> context = Utils::ToLocal(handle(i_isolate->context()));
+  auto maybe = resolver->Reject(context, exception);
+  CHECK_IMPLIES(!maybe.FromMaybe(false), i_isolate->has_scheduled_exception());
+}
+
 void WasmModuleObjectBuilder::OnBytesReceived(const uint8_t* bytes,
                                               size_t size) {
   std::unique_ptr<uint8_t[]> cloned_bytes(new uint8_t[size]);