diff --git a/rtc_base/async_invoker.cc b/rtc_base/async_invoker.cc
index 4cf0aca78d..61c153499f 100644
--- a/rtc_base/async_invoker.cc
+++ b/rtc_base/async_invoker.cc
@@ -46,28 +46,6 @@ void DEPRECATED_AsyncInvoker::OnMessage(Message* msg) {
   delete data;
 }
 
-void DEPRECATED_AsyncInvoker::Flush(Thread* thread,
-                                    uint32_t id /*= MQID_ANY*/) {
-  // If the destructor is waiting for invocations to finish, don't start
-  // running even more tasks.
-  if (destroying_.load(std::memory_order_relaxed))
-    return;
-
-  // Run this on `thread` to reduce the number of context switches.
-  if (Thread::Current() != thread) {
-    thread->Invoke<void>(RTC_FROM_HERE,
-                         [this, thread, id] { Flush(thread, id); });
-    return;
-  }
-
-  MessageList removed;
-  thread->Clear(this, id, &removed);
-  for (MessageList::iterator it = removed.begin(); it != removed.end(); ++it) {
-    // This message was pending on this thread, so run it now.
-    thread->Send(it->posted_from, it->phandler, it->message_id, it->pdata);
-  }
-}
-
 void DEPRECATED_AsyncInvoker::Clear() {
   ThreadManager::Clear(this);
 }
diff --git a/rtc_base/async_invoker.h b/rtc_base/async_invoker.h
index 8a54159a57..e5a3c15cac 100644
--- a/rtc_base/async_invoker.h
+++ b/rtc_base/async_invoker.h
@@ -121,13 +121,6 @@ class DEPRECATED_AsyncInvoker : public MessageHandlerAutoCleanup {
     DoInvokeDelayed(posted_from, thread, std::move(closure), delay_ms, id);
   }
 
-  // Synchronously execute on `thread` all outstanding calls we own
-  // that are pending on `thread`, and wait for calls to complete
-  // before returning. Optionally filter by message id.
-  // The destructor will not wait for outstanding calls, so if that
-  // behavior is desired, call Flush() before destroying this object.
-  void Flush(Thread* thread, uint32_t id = MQID_ANY);
-
   // Cancels any outstanding calls we own that are pending on any thread, and
   // which have not yet started to execute. This does not wait for any calls
   // that have already started executing to complete.
diff --git a/rtc_base/thread_unittest.cc b/rtc_base/thread_unittest.cc
index 87c87e6a02..62f00ec772 100644
--- a/rtc_base/thread_unittest.cc
+++ b/rtc_base/thread_unittest.cc
@@ -851,44 +851,6 @@ TEST_F(DEPRECATED_AsyncInvokeTest,
   EXPECT_FALSE(reentrant_functor_run);
 }
 
-TEST_F(DEPRECATED_AsyncInvokeTest, Flush) {
-  DEPRECATED_AsyncInvoker invoker;
-  AtomicBool flag1;
-  AtomicBool flag2;
-  // Queue two async calls to the current thread.
-  invoker.AsyncInvoke<void>(RTC_FROM_HERE, Thread::Current(), FunctorB(&flag1));
-  invoker.AsyncInvoke<void>(RTC_FROM_HERE, Thread::Current(), FunctorB(&flag2));
-  // Because we haven't pumped messages, these should not have run yet.
-  EXPECT_FALSE(flag1.get());
-  EXPECT_FALSE(flag2.get());
-  // Force them to run now.
-  invoker.Flush(Thread::Current());
-  EXPECT_TRUE(flag1.get());
-  EXPECT_TRUE(flag2.get());
-}
-
-TEST_F(DEPRECATED_AsyncInvokeTest, FlushWithIds) {
-  DEPRECATED_AsyncInvoker invoker;
-  AtomicBool flag1;
-  AtomicBool flag2;
-  // Queue two async calls to the current thread, one with a message id.
-  invoker.AsyncInvoke<void>(RTC_FROM_HERE, Thread::Current(), FunctorB(&flag1),
-                            5);
-  invoker.AsyncInvoke<void>(RTC_FROM_HERE, Thread::Current(), FunctorB(&flag2));
-  // Because we haven't pumped messages, these should not have run yet.
-  EXPECT_FALSE(flag1.get());
-  EXPECT_FALSE(flag2.get());
-  // Execute pending calls with id == 5.
-  invoker.Flush(Thread::Current(), 5);
-  EXPECT_TRUE(flag1.get());
-  EXPECT_FALSE(flag2.get());
-  flag1 = false;
-  // Execute all pending calls. The id == 5 call should not execute again.
-  invoker.Flush(Thread::Current());
-  EXPECT_FALSE(flag1.get());
-  EXPECT_TRUE(flag2.get());
-}
-
 void WaitAndSetEvent(Event* wait_event, Event* set_event) {
   wait_event->Wait(Event::kForever);
   set_event->Set();