I'm enabling more tests on chromium.memory in https://chromium-review.googlesource.com/c/chromium/src/+/987916/

Three tests in services_unittests fail on msan, e.g. 

https://ci.chromium.org/buildbot/tryserver.chromium.linux/linux_chromium_chromeos_msan_rel_ng/674
https://ci.chromium.org/buildbot/tryserver.chromium.linux/linux_chromium_msan_rel_ng/967


Failing tests:


MusDemoTest.CheckMusDemoDraws
GpuHostTest.GpuClientDestroyedWhileChannelRequestInFlight
GpuHostTest.GpuClientDestructionOrder


Seems to be due to a single stack from what I can tell:

ATTENTION: default value of option force_s3tc_enable overridden by environment.
Uninitialized bytes in __interceptor_strlen at offset 20 inside [0x71f000000e00, 3280)
==6223==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x7f2e39f1a4c8 in _init ??:0:0
    #1 0x7f2e39f1f599 in glXMakeCurrent ??:?
    #2 0x7f2e39f1f599 in ?? ??:0
    #3 0x7f2e39f1b7f0 in glXQueryVersion ??:0:0
    #4 0xa4cd447 in gl::GLSurfaceGLX::InitializeOneOff() ./../../ui/gl/gl_surface_glx.cc:423:8
    #5 0x58154bd in ui::GLOzoneGLX::InitializeGLOneOffPlatform() ./../../ui/ozone/platform/x11/gl_ozone_glx.cc:27:8
    #6 0xabe0c0f in gl::init::InitializeGLOneOffPlatform() ./../../ui/gl/init/gl_initializer_ozone.cc:18:26
    #7 0xabdc574 in gl::init::InitializeGLOneOffImplementation(gl::GLImplementation, bool, bool, bool, bool) ./../../ui/gl/init/gl_factory.cc:88:43
    #8 0xabdbbee in gl::init::(anonymous namespace)::InitializeGLOneOffHelper(bool) ./../../ui/gl/init/gl_factory.cc:65:10
    #9 0xabdc09b in gl::init::InitializeGLNoExtensionsOneOff() ./../../ui/gl/init/gl_factory.cc:79:10
    #10 0xb51c4a6 in gpu::GpuInit::InitializeInProcess(base::CommandLine*, gpu::GpuPreferences const&) ./../../gpu/ipc/service/gpu_init.cc:344:8
    #11 0x6cd9296 in viz::VizMainImpl::VizMainImpl(viz::VizMainImpl::Delegate*, viz::VizMainImpl::ExternalDependencies, std::__1::unique_ptr<gpu::GpuInit, std::__1::default_delete<gpu::GpuInit> >) ./../../components/viz/service/main/viz_main_impl.cc:129:16
    #12 0x11dea629 in make_unique<viz::VizMainImpl, nullptr_t, viz::VizMainImpl::ExternalDependencies> ./../../buildtools/third_party/libc++/trunk/include/memory:3079:32
    #13 0x11dea629 in ui::ws::DefaultGpuHost::InitializeVizMain(mojo::InterfaceRequest<viz::mojom::VizMain>) ./../../services/ui/ws/gpu_host.cc:151:0
    #14 0x11df0b05 in Invoke<ui::ws::DefaultGpuHost *, mojo::InterfaceRequest<viz::mojom::VizMain> > ./../../base/bind_internal.h:447:12
    #15 0x11df0b05 in MakeItSo<void (ui::ws::DefaultGpuHost::*)(mojo::InterfaceRequest<viz::mojom::VizMain>), ui::ws::DefaultGpuHost *, mojo::InterfaceRequest<viz::mojom::VizMain> > ./../../base/bind_internal.h:530:0
    #16 0x11df0b05 in void base::internal::Invoker<base::internal::BindState<void (ui::ws::DefaultGpuHost::*)(mojo::InterfaceRequest<viz::mojom::VizMain>), base::internal::UnretainedWrapper<ui::ws::DefaultGpuHost>, base::internal::PassedWrapper<mojo::InterfaceRequest<viz::mojom::VizMain> > >, void ()>::RunImpl<void (ui::ws::DefaultGpuHost::*)(mojo::InterfaceRequest<viz::mojom::VizMain>), std::__1::tuple<base::internal::UnretainedWrapper<ui::ws::DefaultGpuHost>, base::internal::PassedWrapper<mojo::InterfaceRequest<viz::mojom::VizMain> > >, 0ul, 1ul>(void (ui::ws::DefaultGpuHost::*&&)(mojo::InterfaceRequest<viz::mojom::VizMain>), std::__1::tuple<base::internal::UnretainedWrapper<ui::ws::DefaultGpuHost>, base::internal::PassedWrapper<mojo::InterfaceRequest<viz::mojom::VizMain> > >&&, std::__1::integer_sequence<unsigned long, 0ul, 1ul>) ./../../base/bind_internal.h:604:0
    #17 0x6d66c04 in Run ./../../base/callback.h:95:12
    #18 0x6d66c04 in base::debug::TaskAnnotator::RunTask(char const*, base::PendingTask*) ./../../base/debug/task_annotator.cc:61:0
    #19 0x6db8305 in base::MessageLoop::RunTask(base::PendingTask*) ./../../base/message_loop/message_loop.cc:391:25
    #20 0x6db9d9e in DeferOrRunPendingTask ./../../base/message_loop/message_loop.cc:403:5
    #21 0x6db9d9e in base::MessageLoop::DoWork() ./../../base/message_loop/message_loop.cc:447:0
    #22 0x6dbeb12 in base::MessagePumpDefault::Run(base::MessagePump::Delegate*) ./../../base/message_loop/message_pump_default.cc:37:31
    #23 0x6e32e4f in base::RunLoop::Run() ./../../base/run_loop.cc:130:14
    #24 0x6ed2f45 in base::Thread::ThreadMain() ./../../base/threading/thread.cc:338:3
    #25 0x6ec9357 in base::(anonymous namespace)::ThreadFunc(void*) ./../../base/threading/platform_thread_posix.cc:76:13
    #26 0x7f2e43f26183 in start_thread /build/eglibc-SvCtMH/eglibc-2.19/nptl/pthread_create.c:312:0
    #27 0x7f2e3efdfffc in clone /build/eglibc-SvCtMH/eglibc-2.19/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:111:0
  Uninitialized value was created by a heap allocation
    #0 0x564e3d in __interceptor_malloc /b/build/slave/linux_upload_clang/build/src/third_party/llvm/compiler-rt/lib/msan/msan_interceptors.cc:915:3
    #1 0x7f2e39f1fae3 in glXMakeCurrent ??:?
    #2 0x7f2e39f1fae3 in ?? ??:0
SUMMARY: MemorySanitizer: use-of-uninitialized-value (/usr/lib/x86_64-linux-gnu/mesa/libGL.so.1+0x194c8)




Might either be easy to fix, or a false positive due to the gl driver not being instrumented, but I think we instrument all the libs.

cc'ing the gpu owners from components/viz/OWNERS.