Chrome Version: 69.0.3447.2
OS: macOS 10.13.4

What steps will reproduce the problem?
(1) views-browser-windows enabled
(2) Opened a G+ tab
(3) Browser process hang

Sample attached. Most prominently we have

    +                                                                       2413 content::GpuProcessTransportFactory::CreateLayerTreeFrameSink(base::WeakPtr<ui::Compositor>)  (in Google Chrome Framework)  load address 0x10dd88000 + 0xf77f98  [callback_forward.h:11]
    +                                                                         2413 content::BrowserGpuChannelHostFactory::EstablishGpuChannel(base::OnceCallback<void (scoped_refptr<gpu::GpuChannelHost>)>)  (in Google Chrome Framework)  load address 0x10dd88000 + 0xc5a722  [callback_forward.h:11]
    +                                                                           2413 base::internal::Invoker<base::internal::BindState<void (content::GpuProcessTransportFactory::*)(base::WeakPtr<ui::Compositor>, bool, scoped_refptr<gpu::GpuChannelHost>), base::WeakPtr<content::GpuProcessTransportFactory>, base::WeakPtr<ui::Compositor>, bool>, void (scoped_refptr<gpu::GpuChannelHost>)>::RunOnce(base::internal::BindStateBase*, scoped_refptr<gpu::GpuChannelHost>&&)  (in Google Chrome Framework)  load address 0x10dd88000 + 0xf7a806  [scoped_refptr.h:207]
    +                                                                             2413 content::GpuProcessTransportFactory::EstablishedGpuChannel(base::WeakPtr<ui::Compositor>, bool, scoped_refptr<gpu::GpuChannelHost>)  (in Google Chrome Framework)  load address 0x10dd88000 + 0xf788b8  [gpu_process_transport_factory.cc:447]
    +                                                                               2413 ui::ContextProviderCommandBuffer::BindToCurrentThread()  (in Google Chrome Framework)  load address 0x10dd88000 + 0x10eea94  [context_provider_command_buffer.cc:231]
    +                                                                                 2413 gpu::CommandBufferProxyImpl::Initialize(unsigned long long, gpu::CommandBufferProxyImpl*, gpu::SchedulingPriority, gpu::ContextCreationAttribs const&, GURL const&)  (in Google Chrome Framework)  load address 0x10dd88000 + 0x7d1e0c  [command_buffer_proxy_impl.cc:130]
    +                                                                                   2413 gpu::GpuChannelHost::Send(IPC::Message*)  (in Google Chrome Framework)  load address 0x10dd88000 + 0x7d6f41  [gpu_channel_host.cc:85]
    +                                                                                     2413 base::WaitableEvent::Wait()  (in Google Chrome Framework)  load address 0x10dd88000 + 0x22356bf  [waitable_event_mac.cc:107]
    +                                                                                       2413 base::WaitableEvent::TimedWaitUntil(base::TimeTicks const&)  (in Google Chrome Framework)  load address 0x10dd88000 + 0x2235795  [waitable_event_mac.cc:149]
    +                                                                                         2413 mach_msg  (in libsystem_kernel.dylib) + 60  [0x7fff7c6ff724]
    +                                                                                           2413 mach_msg_trap  (in libsystem_kernel.dylib) + 10  [0x7fff7c70020a]

in the main thread and

    +                       2413 base::internal::Invoker<base::internal::BindState<void (content::SessionStorageContextMojo::*)(int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, mojo::InterfaceRequest<content::mojom::SessionStorageNamespace>), base::internal::UnretainedWrapper<content::SessionStorageContextMojo>, int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, mojo::InterfaceRequest<content::mojom::SessionStorageNamespace> >, void ()>::RunOnce(base::internal::BindStateBase*)  (in Google Chrome Framework)  load address 0x10dd88000 + 0xbac209  [handle.h:167]
    +                         2413 content::SessionStorageContextMojo::OpenSessionStorage(int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, mojo::InterfaceRequest<content::mojom::SessionStorageNamespace>)  (in Google Chrome Framework)  load address 0x10dd88000 + 0xbb8787  [memory:2603]
    +                           1207 content::SessionStorageContextMojo::PurgeUnusedWrappersIfNeeded()  (in Google Chrome Framework)  load address 0x10dd88000 + 0xbb8af0  [memory:2603]
    +                           1204 content::SessionStorageContextMojo::PurgeUnusedWrappersIfNeeded()  (in Google Chrome Framework)  load address 0x10dd88000 + 0xbb8b04  [__tree:859]
    +                           2 content::SessionStorageContextMojo::PurgeUnusedWrappersIfNeeded()  (in Google Chrome Framework)  load address 0x10dd88000 + 0xbb8afc  [session_storage_namespace_impl_mojo.h:114]


in the IO thread

Maybe something related to the recent MacViews compositor changes?