review updates

Author: George Wright

fml/message_loop.cc

@@ -80,4 +80,5 @@ TaskQueueId MessageLoop::GetCurrentTaskQueueId() {
          "this thread prior to message loop use.";
   return loop->GetLoopImpl()->GetTaskQueueId();
 }
+
 }  // namespace fml

fml/message_loop_impl.cc

@@ -145,8 +145,4 @@ TaskQueueId MessageLoopImpl::GetTaskQueueId() const {
   return queue_id_;
 }
 
-fml::RefPtr<MessageLoopImpl> MessageLoopImpl::GetLoopImpl(MessageLoop& message_loop) {
-  return message_loop.GetLoopImpl();
-}
-
 }  // namespace fml

fml/message_loop_impl.h

@@ -58,8 +58,6 @@ class MessageLoopImpl : public Wakeable,
  protected:
   MessageLoopImpl();
 
-  static fml::RefPtr<MessageLoopImpl> GetLoopImpl(MessageLoop& loop);
-
  private:
   fml::RefPtr<MessageLoopTaskQueues> task_queue_;
   TaskQueueId queue_id_;

fml/platform/fuchsia/message_loop_fuchsia.cc

@@ -35,15 +35,4 @@ void MessageLoopFuchsia::WakeUp(fml::TimePoint time_point) {
   FML_DCHECK(status == ZX_OK);
 }
 
-// TODO(gw280): This is needed in order to get the underlying async::Loop object to pass to other Fuchsia components,
-// such as the Trace component.
-async::Loop* MessageLoopFuchsia::FuchsiaLoopForMessageLoop(MessageLoop& message_loop) {
-  MessageLoopFuchsia* loop_impl = (MessageLoopFuchsia*)MessageLoopImpl::GetLoopImpl(message_loop).get();
-  return loop_impl->GetAsyncLoop();
-}
-
-async::Loop* MessageLoopFuchsia::GetAsyncLoop() {
-  return &loop_;
-}
-
 }  // namespace fml

fml/platform/fuchsia/message_loop_fuchsia.h

@@ -13,9 +13,6 @@
 namespace fml {
 
 class MessageLoopFuchsia : public MessageLoopImpl {
- public:
-  static async::Loop* FuchsiaLoopForMessageLoop(MessageLoop& message_loop);
-
  private:
   MessageLoopFuchsia();
 
@@ -27,8 +24,6 @@ class MessageLoopFuchsia : public MessageLoopImpl {
 
   void WakeUp(fml::TimePoint time_point) override;
 
-  async::Loop* GetAsyncLoop();
-
   async::Loop loop_;
 
   FML_FRIEND_MAKE_REF_COUNTED(MessageLoopFuchsia);

shell/platform/fuchsia/flutter/main.cc

@@ -5,13 +5,12 @@
 #define FML_USED_ON_EMBEDDER
 
 #include <lib/async-loop/cpp/loop.h>
+#include <lib/async-loop/default.h>
 #include <lib/trace-provider/provider.h>
 #include <lib/trace/event.h>
 
 #include <cstdlib>
 
-#include "flutter/fml/platform/fuchsia/message_loop_fuchsia.h"
-
 #include "runner.h"
 #include "runtime/dart/utils/tempfs.h"
 
@@ -23,9 +22,10 @@ int main(int argc, char const* argv[]) {
   {
     TRACE_DURATION("flutter", "CreateTraceProvider");
     bool already_started;
+    async::Loop loop(&kAsyncLoopConfigAttachToCurrentThread);
     // Use CreateSynchronously to prevent loss of early events.
     trace::TraceProviderWithFdio::CreateSynchronously(
-        fml::MessageLoopFuchsia::FuchsiaLoopForMessageLoop(message_loop)->dispatcher(), "flutter_runner", &provider, &already_started);
+        loop.dispatcher(), "flutter_runner", &provider, &already_started);
   }
 
   // Set up the process-wide /tmp memfs.

shell/platform/fuchsia/flutter/runner.cc

@@ -18,7 +18,6 @@
 #include <utility>
 
 #include "flutter/fml/make_copyable.h"
-#include "flutter/fml/platform/fuchsia/message_loop_fuchsia.h"
 #include "flutter/lib/ui/text/font_collection.h"
 #include "flutter/runtime/dart_vm.h"
 #include "lib/sys/cpp/component_context.h"
@@ -284,8 +283,9 @@ bool Runner::SetupTZDataInternal() {
 #if !defined(DART_PRODUCT)
 void Runner::SetupTraceObserver() {
   trace_observer_ = std::make_unique<trace::TraceObserver>();
-  auto loop = fml::MessageLoopFuchsia::FuchsiaLoopForMessageLoop(message_loop_);
-  trace_observer_->Start(loop->dispatcher(), [runner = this]() {
+  ASSERT_TRUE(message_loop_.GetTaskRunner()->RunsTasksOnCurrentThread());
+  async::Loop loop(&kAsyncLoopConfigAttachToCurrentThread);
+  trace_observer_->Start(loop.dispatcher(), [runner = this]() {
     if (!trace_is_category_enabled("dart:profiler")) {
       return;
     }