Support passing native modules to JSContext

Reviewed By: amnn

Differential Revision: D4561036

fbshipit-source-id: b096a222103e895b14cba1ec5b2bb6e72dd72c37

ReactCommon/cxxreact/Instance.cpp

@@ -2,6 +2,7 @@
 
 #include "Instance.h"
 
+#include "CxxMessageQueue.h"
 #include "Executor.h"
 #include "MethodCall.h"
 #include "RecoverableError.h"
@@ -36,6 +37,15 @@ void Instance::initializeBridge(
     std::shared_ptr<ModuleRegistry> moduleRegistry) {
   callback_ = std::move(callback);
 
+  if (!nativeQueue) {
+    // TODO pass down a thread/queue from java, instead of creating our own.
+
+    auto queue = std::make_unique<CxxMessageQueue>();
+    std::thread t(queue->getUnregisteredRunLoop());
+    t.detach();
+    nativeQueue = std::move(queue);
+  }
+
   jsQueue->runOnQueueSync(
     [this, &jsef, moduleRegistry, jsQueue,
      nativeQueue=folly::makeMoveWrapper(std::move(nativeQueue))] () mutable {