Add ability to use movable only functors in rtc::Thread::Invoke(...)

Add support for movable only functors with void return type. Non void
return type is already supported.

Bug: webrtc:10138
Change-Id: If2ae2b5ab7244a0e932bceff7d9853c030805688
Reviewed-on: https://webrtc-review.googlesource.com/c/116740
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26186}
diff --git a/rtc_base/timeutils_unittest.cc b/rtc_base/timeutils_unittest.cc
index 9e7de06..a2e9a3f 100644
--- a/rtc_base/timeutils_unittest.cc
+++ b/rtc_base/timeutils_unittest.cc
@@ -272,7 +272,7 @@
   auto functor = [&message_handler_dispatched] {
     message_handler_dispatched.Set();
   };
-  FunctorMessageHandler<void, decltype(functor)> handler(functor);
+  FunctorMessageHandler<void, decltype(functor)> handler(std::move(functor));
   worker->PostDelayed(RTC_FROM_HERE, 60000, &handler);
 
   // Wait for a bit for the worker thread to be started and enter its socket