Actually register the BroadcastChannel pre-finalizer.

third_party/WebKit/Source/modules/broadcastchannel/BroadcastChannel.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/broadcastchannel/BroadcastChannel.h"
 
 #include "bindings/core/v8/SerializedScriptValue.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/events/EventQueue.h"
 #include "core/events/MessageEvent.h"
@@ skipping 103 matching lines @@
     close();
 }
 
 BroadcastChannel::BroadcastChannel(ExecutionContext* executionContext, const String& name)
     : ActiveScriptWrappable(this)
     , ContextLifecycleObserver(executionContext)
     , m_origin(executionContext->getSecurityOrigin())
     , m_name(name)
     , m_binding(this)
 {
+    ThreadState::current()->registerPreFinalizer(this);
+
     mojom::blink::BroadcastChannelProviderPtr& provider = getThreadSpecificProvider();
 
     // Local BroadcastChannelClient for messages send from the browser to this channel.
     mojom::blink::BroadcastChannelClientAssociatedPtrInfo localClientInfo;
     m_binding.Bind(&localClientInfo, provider.associated_group());
     m_binding.set_connection_error_handler(convertToBaseCallback(WTF::bind(&BroadcastChannel::onError, wrapWeakPersistent(this))));
 
     // Remote BroadcastChannelClient for messages send from this channel to the browser.
     mojom::blink::BroadcastChannelClientAssociatedPtrInfo remoteClientInfo;
     mojo::AssociatedInterfaceRequest<mojom::blink::BroadcastChannelClient> remoteCientRequest;
     provider.associated_group()->CreateAssociatedInterface(mojo::AssociatedGroup::WILL_PASS_REQUEST, &remoteClientInfo, &remoteCientRequest);
     m_remoteClient.Bind(std::move(remoteClientInfo));
     m_remoteClient.set_connection_error_handler(convertToBaseCallback(WTF::bind(&BroadcastChannel::onError, wrapWeakPersistent(this))));
 
     provider->ConnectToChannel(m_origin, m_name, std::move(localClientInfo), std::move(remoteCientRequest));
 }
 
 } // namespace blink