Almost certainly because of https://chromium-review.googlesource.com/c/chromium/src/+/1018240 which reenables the test.

Here is the crash stack:
Received signal 11 SEGV_MAPERR 000000000000
0   Chromium Framework                  0x0000000115d7e91c base::debug::StackTrace::StackTrace(unsigned long) + 28
1   Chromium Framework                  0x0000000115d7e751 base::debug::(anonymous namespace)::StackDumpSignalHandler(int, __siginfo*, void*) + 2401
2   libsystem_platform.dylib            0x00007fff5a75df5a _sigtramp + 26
3   Chromium Framework                  0x000000011659cca5 IPC::ChannelProxy::Context::TryFilters(IPC::Message const&) + 117
4   Chromium Framework                  0x000000011356cfce viz::mojom::GpuServiceStubDispatch::Accept(viz::mojom::GpuService*, mojo::Message*) + 1358
5   Chromium Framework                  0x00000001166ae1b6 mojo::InterfaceEndpointClient::HandleValidatedMessage(mojo::Message*) + 950
6   Chromium Framework                  0x00000001166ada86 mojo::FilterChain::Accept(mojo::Message*) + 150
7   Chromium Framework                  0x00000001166af5e5 mojo::InterfaceEndpointClient::HandleIncomingMessage(mojo::Message*) + 117
8   Chromium Framework                  0x00000001166b5c7c mojo::internal::MultiplexRouter::ProcessIncomingMessage(mojo::internal::MultiplexRouter::MessageWrapper*, mojo::internal::MultiplexRouter::ClientCallBehavior, base::SequencedTaskRunner*) + 1420
9   Chromium Framework                  0x00000001166b5080 mojo::internal::MultiplexRouter::Accept(mojo::Message*) + 368
10  Chromium Framework                  0x00000001166ada86 mojo::FilterChain::Accept(mojo::Message*) + 150
11  Chromium Framework                  0x00000001166a8d93 mojo::Connector::ReadSingleMessage(unsigned int*) + 419
12  Chromium Framework                  0x00000001166a97e1 mojo::Connector::ReadAllAvailableMessages() + 97
13  Chromium Framework                  0x00000001166a9699 mojo::Connector::OnHandleReadyInternal(unsigned int) + 137
14  Chromium Framework                  0x000000011355a5c7 mojo::SimpleWatcher::DiscardReadyState(base::RepeatingCallback<void (unsigned int)> const&, unsigned int, mojo::HandleSignalsState const&) + 103
15  Chromium Framework                  0x00000001165ba8dc mojo::SimpleWatcher::OnHandleReady(int, unsigned int, mojo::HandleSignalsState const&) + 332
16  Chromium Framework                  0x00000001165bad16 mojo::SimpleWatcher::Context::Notify(unsigned int, MojoHandleSignalsState, unsigned int) + 854
17  Chromium Framework                  0x00000001165b98e3 mojo::SimpleWatcher::Context::CallNotify(MojoTrapEvent const*) + 35
18  Chromium Framework                  0x00000001135b8977 mojo::edk::WatcherDispatcher::InvokeWatchCallback(unsigned long, unsigned int, mojo::edk::HandleSignalsState const&, unsigned int) + 119
19  Chromium Framework                  0x00000001135b7f82 mojo::edk::Watch::InvokeCallback(unsigned int, mojo::edk::HandleSignalsState const&, unsigned int) + 194
20  Chromium Framework                  0x00000001135b2ce6 mojo::edk::RequestContext::~RequestContext() + 1030
21  Chromium Framework                  0x00000001135a2e87 mojo::edk::NodeChannel::OnChannelMessage(void const*, unsigned long, std::__1::vector<mojo::edk::ScopedPlatformHandle, std::__1::allocator<mojo::edk::ScopedPlatformHandle> >) + 343
22  Chromium Framework                  0x0000000113591b78 mojo::edk::Channel::OnReadComplete(unsigned long, unsigned long*) + 600
23  Chromium Framework                  0x00000001135bffc7 mojo::edk::(anonymous namespace)::ChannelPosix::OnFileCanReadWithoutBlocking(int) + 519
24  Chromium Framework                  0x0000000115dc3620 base::MessagePumpLibevent::OnLibeventNotification(int, short, void*) + 352
25  Chromium Framework                  0x0000000115ea10fc event_base_loop + 1196
26  Chromium Framework                  0x0000000115dc3992 base::MessagePumpLibevent::Run(base::MessagePump::Delegate*) + 434
27  Chromium Framework                  0x0000000115dbf004 base::MessageLoop::Run(bool) + 132
28  Chromium Framework                  0x0000000115dff219 base::RunLoop::Run() + 249
29  Chromium Framework                  0x0000000115e4d23e base::Thread::Run(base::RunLoop*) + 206
30  Chromium Framework                  0x0000000115e4d77e base::Thread::ThreadMain() + 782
31  Chromium Framework                  0x0000000115e482df base::(anonymous namespace)::ThreadFunc(void*) + 95
32  libsystem_pthread.dylib             0x00007fff5a767661 _pthread_body + 340
33  libsystem_pthread.dylib             0x00007fff5a76750d _pthread_body + 0
34  libsystem_pthread.dylib             0x00007fff5a766bf9 thread_start + 13
[end of stack trace]

Is this the only test that fails this way?
There's nothing in this backtrace that seems particularly specific to the test in question.
Also, builder link doesn't work.

Sorry for the link, S-o-M was unhelpful here.

Builder:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac%20FYI%20Experimental%20Release%20(Intel)

First failing build:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac%20FYI%20Experimental%20Release%20%28Intel%29/1628

Yes, it is the only test failing.

Maybe a null filter was added by some infrastructure specific to this test?

Kind of looks like the backtrace comes from the "sad canvas" test.
The VP9 test seems to just not match expectations.

My contribution to this problem is fixed.
There is still an issue on mac, which is tracked in a separate bug: crbug.com/774809