From 6301223ceeb13906436041f421bdfe1c5bbfb941 Mon Sep 17 00:00:00 2001
From: Kaushik Iska <iska.kaushik@gmail.com>
Date: Thu, 25 Mar 2021 16:59:00 -0500
Subject: [PATCH] [tracing] Add trace events for DartIsolate::HandleMessage
 (flutter/engine#25241)

This captures majority of the non frame related workload
happening on the UI thread.
---
 engine/src/flutter/runtime/dart_isolate.cc | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/engine/src/flutter/runtime/dart_isolate.cc b/engine/src/flutter/runtime/dart_isolate.cc
index d5e70379bbc..658423f178c 100644
--- a/engine/src/flutter/runtime/dart_isolate.cc
+++ b/engine/src/flutter/runtime/dart_isolate.cc
@@ -445,8 +445,13 @@ void DartIsolate::SetMessageHandlingTaskRunner(
 
   message_handling_task_runner_ = runner;
 
-  message_handler().Initialize(
-      [runner](std::function<void()> task) { runner->PostTask(task); });
+  message_handler().Initialize([runner](std::function<void()> task) {
+    TRACE_EVENT0("flutter", "DartIsolate::PostMessage");
+    runner->PostTask([task = std::move(task)]() {
+      TRACE_EVENT0("flutter", "DartIsolate::HandleMessage");
+      task();
+    });
+  });
 }
 
 // Updating thread names here does not change the underlying OS thread names.