Revert of Make RtcEventLogImpl to use a TaskQueue instead of a helper-thread

webrtc/pc/peerconnection.cc

Index: webrtc/pc/peerconnection.cc
diff --git a/webrtc/pc/peerconnection.cc b/webrtc/pc/peerconnection.cc
index 99b87c0012edbe2400f172f08822588199966c35..e22a09ece06998d12cd2db9dba82c4f0231b368c 100644
--- a/webrtc/pc/peerconnection.cc
+++ b/webrtc/pc/peerconnection.cc
@@ -1337,11 +1337,11 @@
       rtc::Bind(&cricket::PortAllocator::DiscardCandidatePool,
                 port_allocator_.get()));
 
-  factory_->worker_thread()->Invoke<void>(RTC_FROM_HERE, [this] {
-    call_.reset();
-    // The event log must outlive call (and any other object that uses it).
-    event_log_.reset();
-  });
+  factory_->worker_thread()->Invoke<void>(RTC_FROM_HERE,
+                                          [this] { call_.reset(); });
+
+  // The event log must outlive call (and any other object that uses it).
+  event_log_.reset();
 }
 
 void PeerConnection::OnSessionStateChange(WebRtcSession* /*session*/,