Shutdown crash in content::GpuChannelHost::Send

I'm now seeing this shutdown crash occasionally:

#0 0x00000000009f7a30 in ?? ()
#1 0x00007ffff30d714e in content::GpuChannelHost::Send (this=0xa27bb0, msg=0xa3a840) at ../../../../third_party/chromium/src/content/common/gpu/client/gpu_channel_host.cc:98
#2 0x00007ffff30cb2c6 in content::CommandBufferProxyImpl::Send (this=0x7fff800203e0, msg=<optimised out>)
    at ../../../../third_party/chromium/src/content/common/gpu/client/command_buffer_proxy_impl.cc:488
#3 0x00007ffff30cb84a in content::CommandBufferProxyImpl::SetMemoryAllocationChangedCallback(base::Callback<void (gpu::MemoryAllocation const&)> const&) (this=0x7fff800203e0,
    callback=...) at ../../../../third_party/chromium/src/content/common/gpu/client/command_buffer_proxy_impl.cc:96
#4 0x00007ffff30cdfa1 in content::ContextProviderCommandBuffer::~ContextProviderCommandBuffer (this=this@entry=0x229e200, __in_chrg=<optimised out>)
    at ../../../../third_party/chromium/src/content/common/gpu/client/context_provider_command_buffer.cc:68
#5 0x00007ffff30ce189 in content::ContextProviderCommandBuffer::~ContextProviderCommandBuffer (this=0x229e200, __in_chrg=<optimised out>)
    at ../../../../third_party/chromium/src/content/common/gpu/client/context_provider_command_buffer.cc:71
#6 0x00007ffff2463382 in DeleteInternal (x=0x229e200) at ../../../../third_party/chromium/src/base/memory/ref_counted.h:192
#7 Destruct (x=0x229e200) at ../../../../third_party/chromium/src/base/memory/ref_counted.h:155
#8 Release (this=0x229e208) at ../../../../third_party/chromium/src/base/memory/ref_counted.h:183
#9 Release (ptr=0x229e200) at ../../../../third_party/chromium/src/base/memory/ref_counted.h:383
#10 ~scoped_refptr (this=0x7fff800097f8, __in_chrg=<optimised out>) at ../../../../third_party/chromium/src/base/memory/ref_counted.h:291
#11 ~FetchTextureResourcesTask (this=0x7fff800097e0, __in_chrg=<optimised out>) at ../../../../shared/browser/compositor/oxide_compositor_utils.cc:90
#12 ~FetchTextureResourcesTask (this=0x7fff800097e0, __in_chrg=<optimised out>) at ../../../../shared/browser/compositor/oxide_compositor_utils.cc:93
#13 DeleteInternal (x=0x7fff800097e0) at ../../../../third_party/chromium/src/base/memory/ref_counted.h:192
#14 Destruct (x=0x7fff800097e0) at ../../../../third_party/chromium/src/base/memory/ref_counted.h:155
#15 Release (this=0x7fff800097e8) at ../../../../third_party/chromium/src/base/memory/ref_counted.h:183
#16 Release (o=0x7fff800097e0) at ../../../../third_party/chromium/src/base/bind_helpers.h:462
#17 ~BindState (this=0x7fff7d51cd40, __in_chrg=<optimised out>) at ../../../../third_party/chromium/src/base/bind_internal.h:1908
#18 base::internal::BindState<base::internal::RunnableAdapter<void (oxide::FetchTextureResourcesTask::*)(unsigned int)>, void (oxide::FetchTextureResourcesTask*, unsigned int), void (oxide::FetchTextureResourcesTask*, unsigned int)>::~BindState() (this=0x7fff7d51cd40, __in_chrg=<optimised out>)
    at ../../../../third_party/chromium/src/base/bind_internal.h:1909
#19 0x00007ffff24e9acd in ~Callback (this=0x7fffffffce28, __in_chrg=<optimised out>) at ../../../../third_party/chromium/src/base/callback.h:366
#20 base::PendingTask::~PendingTask (this=0x7fffffffce10, __in_chrg=<optimised out>) at ../../../../third_party/chromium/src/base/pending_task.cc:33
#21 0x00007ffff24dc8a8 in base::MessageLoop::DeletePendingTasks (this=0x9e3fe0) at ../../../../third_party/chromium/src/base/message_loop/message_loop.cc:474
#22 0x00007ffff24dd0eb in base::MessageLoop::~MessageLoop (this=this@entry=0x9e3fe0, __in_chrg=<optimised out>)
    at ../../../../third_party/chromium/src/base/message_loop/message_loop.cc:167
#23 0x00007ffff24dd719 in base::MessageLoop::~MessageLoop (this=0x9e3fe0, __in_chrg=<optimised out>)
    at ../../../../third_party/chromium/src/base/message_loop/message_loop.cc:186
#24 0x00007ffff246a989 in oxide::BrowserMainParts::~BrowserMainParts (this=0x9d9350, __in_chrg=<optimised out>) at ../../../../shared/browser/oxide_browser_main_parts.cc:280
#25 0x00007ffff2d6aee2 in operator() (this=0x9d8fe0, ptr=<optimised out>) at ../../../../third_party/chromium/src/base/memory/scoped_ptr.h:127
#26 ~scoped_ptr_impl (this=0x9d8fe0, __in_chrg=<optimised out>) at ../../../../third_party/chromium/src/base/memory/scoped_ptr.h:221
#27 ~scoped_ptr (this=0x9d8fe0, __in_chrg=<optimised out>) at ../../../../third_party/chromium/src/base/memory/scoped_ptr.h:311
#28 content::BrowserMainLoop::~BrowserMainLoop (this=this@entry=0x9d8f60, __in_chrg=<optimised out>)
    at ../../../../third_party/chromium/src/content/browser/browser_main_loop.cc:371
#29 0x00007ffff2d6aef9 in content::BrowserMainLoop::~BrowserMainLoop (this=0x9d8f60, __in_chrg=<optimised out>)
    at ../../../../third_party/chromium/src/content/browser/browser_main_loop.cc:377
#30 0x00007ffff2d71217 in operator() (this=0x9d9248, ptr=<optimised out>) at ../../../../third_party/chromium/src/base/memory/scoped_ptr.h:127
#31 reset (p=0x0, this=0x9d9248) at ../../../../third_party/chromium/src/base/memory/scoped_ptr.h:247
#32 reset (p=0x0, this=0x9d9248) at ../../../../third_party/chromium/src/base/memory/scoped_ptr.h:376
#33 content::BrowserMainRunnerImpl::Shutdown (this=0x9d9230) at ../../../../third_party/chromium/src/content/browser/browser_main_runner.cc:266
#34 0x00007ffff246bb65 in oxide::BrowserProcessMainImpl::Shutdown (this=0x7ffff5ee4680 <oxide::BrowserProcessMain::GetInstance()::g_instance>)
    at ../../../../shared/browser/oxide_browser_process_main.cc:462
#35 0x00007ffff79787e5 in qt_call_post_routines () at kernel/qcoreapplication.cpp:296
#36 0x00007ffff797903e in QCoreApplication::~QCoreApplication (this=0x7fffffffd5d0, __in_chrg=<optimised out>) at kernel/qcoreapplication.cpp:779
#37 0x0000000000407d06 in main (argc=<optimised out>, argv=<optimised out>) at /home/chr1s/src/oxide/frame-refactor/qt/tests/qmltests/main.cc:261

It's probably introduced by the fixes for bug 1337506