This test is failing due to a flaky memory leak in the mojo code stack.

Direct leak of 848 byte(s) in 2 object(s) allocated from:
    #0 0x7423db in operator new(unsigned long) (/b/swarming/w/irIWSHCN/out/Release/unit_tests+0x7423db)
    #1 0xfd50402 in IPC::MojoBootstrap::Create(mojo::ScopedHandleBase<mojo::MessagePipeHandle>, IPC::Channel::Mode, IPC::MojoBootstrap::Delegate*, scoped_refptr<base::SingleThreadTaskRunner> const&) ipc/ipc_mojo_bootstrap.cc:691:7
    #2 0xfd1d3c6 in IPC::ChannelMojo::ChannelMojo(mojo::ScopedHandleBase<mojo::MessagePipeHandle>, IPC::Channel::Mode, IPC::Listener*, scoped_refptr<base::SingleThreadTaskRunner> const&) ipc/ipc_channel_mojo.cc:277:7
    #3 0xfd2200c in Create ipc/ipc_channel_mojo.cc:249:11
    #4 0xfd2200c in IPC::(anonymous namespace)::MojoChannelFactory::BuildChannel(IPC::Listener*) ipc/ipc_channel_mojo.cc:60
    #5 0xfd32884 in IPC::ChannelProxy::Context::CreateChannel(std::__1::unique_ptr<IPC::ChannelFactory, std::__1::default_delete<IPC::ChannelFactory> >) ipc/ipc_channel_proxy.cc:79:23
    #6 0xfd373cb in IPC::ChannelProxy::Init(std::__1::unique_ptr<IPC::ChannelFactory, std::__1::default_delete<IPC::ChannelFactory> >, bool) ipc/ipc_channel_proxy.cc:490:15
    #7 0x12ee1fb0 in content::ChildThreadImpl::ConnectChannel(bool, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) content/child/child_thread_impl.cc:380:15
    #8 0x12ee0574 in content::ChildThreadImpl::Init(content::ChildThreadImpl::Options const&) content/child/child_thread_impl.cc:514:3
    #9 0xb3af1d3 in content::UtilityThreadImpl::UtilityThreadImpl(content::InProcessChildThreadParams const&) content/utility/utility_thread_impl.cc:48:7
    #10 0xb3adcf6 in content::InProcessUtilityThread::InitInternal() content/utility/in_process_utility_thread.cc:50:39
    #11 0xe258c31 in Run base/callback.h:389:12
    #12 0xe258c31 in base::debug::TaskAnnotator::RunTask(char const*, base::PendingTask const&) base/debug/task_annotator.cc:51
    #13 0xe0d2475 in base::MessageLoop::RunTask(base::PendingTask const&) base/message_loop/message_loop.cc:496:19
    #14 0xe0d2fb5 in base::MessageLoop::DeferOrRunPendingTask(base::PendingTask) base/message_loop/message_loop.cc:505:5
    #15 0xe0d3fce in base::MessageLoop::DoWork() base/message_loop/message_loop.cc:629:13
    #16 0xe0dcb58 in base::MessagePumpDefault::Run(base::MessagePump::Delegate*) base/message_loop/message_pump_default.cc:35:31
    #17 0xe0d1692 in base::MessageLoop::RunHandler() base/message_loop/message_loop.cc:459:10
    #18 0xe14da65 in base::RunLoop::Run() base/run_loop.cc:35:10
    #19 0xe1be78b in base::Thread::Run(base::RunLoop*) base/threading/thread.cc:205:13
    #20 0xe1becc4 in base::Thread::ThreadMain() base/threading/thread.cc:260:3
    #21 0xe1ae952 in base::(anonymous namespace)::ThreadFunc(void*) base/threading/platform_thread_posix.cc:70:13
    #22 0x7fd625790e99 in start_thread /build/eglibc-oqps9y/eglibc-2.15/nptl/pthread_create.c:308

I'll look at this. 

Detected 4 new flakes for test/step "DownloadProtectionServiceTest.CheckClientDownloadZip". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyPwsSBUZsYWtlIjREb3dubG9hZFByb3RlY3Rpb25TZXJ2aWNlVGVzdC5DaGVja0NsaWVudERvd25sb2FkWmlwDA. This message was posted automatically by the chromium-try-flakes app.

Merging into a new bug which is filed against the underlying cause of the flakiness.