First failing build
Mac
https://uberchromegw.corp.google.com/i/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%29/builds/49701
ChromeOS
https://uberchromegw.corp.google.com/i/chromium.chromiumos/builders/linux-chromeos-dbg/builds/4160

Example
https://chromium-swarm.appspot.com/task?id=3b913fc4e5f1c410&refresh=10&show_raw=1

 RUN      ] PlatformAppBrowserTest.AppWithContextMenuClicked
[94452:51203:0208/183933.799069:WARNING:mac_util.mm(226)] Failed to set backup exclusion for file '/private/var/folders/9x/6c6sv3cj4j53wzpzthbp4ksm0000gm/T/.org.chromium.Chromium.7eA2gH/du59quw/Default/History': Error Domain=NSOSStatusErrorDomain Code=-50 "The operation couldn’t be completed. (OSStatus error -50.)" (paramErr: error in user parameter list) (-50)
[94452:7427:0208/183933.838480:WARNING:notification_platform_bridge_mac.mm(510)] AlertNotificationService: XPC connection invalidated.
[94452:51203:0208/183934.388563:WARNING:mac_util.mm(226)] Failed to set backup exclusion for file '/private/var/folders/9x/6c6sv3cj4j53wzpzthbp4ksm0000gm/T/.org.chromium.Chromium.7eA2gH/du59quw/Default/Favicons': Error Domain=NSOSStatusErrorDomain Code=-50 "The operation couldn’t be completed. (OSStatus error -50.)" (paramErr: error in user parameter list) (-50)
[94474:771:0208/183934.572359:ERROR:vt_video_encode_accelerator_mac.cc(517)]  VTCompressionSessionCreate failed: -12908
[94474:771:0208/183934.947259:ERROR:mac_util.mm(142)] Couldn't get the sRGB color space
[94452:771:0208/183935.687333:INFO:chrome_cryptauth_service.cc(231)] Profile is not authenticated yet; waiting before starting CryptAuth managers.
[94452:40963:0208/183935.721806:ERROR:leak_tracker.h(101)] Leaked 0x7ff2da911fa8 which was allocated by:
[94452:40963:0208/183935.721842:ERROR:leak_tracker.h(102)] 0   libbase.dylib                       0x00000001237fc28e base::debug::StackTrace::StackTrace(unsigned long) + 174
1   libbase.dylib                       0x00000001237fc34d base::debug::StackTrace::StackTrace(unsigned long) + 29
2   libbase.dylib                       0x00000001237fa7cc base::debug::StackTrace::StackTrace() + 28
3   browser_tests                       0x000000010afefe7f base::debug::LeakTracker<SystemURLRequestContextGetter>::LeakTracker() + 47
4   browser_tests                       0x000000010afe0665 base::debug::LeakTracker<SystemURLRequestContextGetter>::LeakTracker() + 21
5   browser_tests                       0x000000010afe063b SystemURLRequestContextGetter::SystemURLRequestContextGetter(IOThread*) + 91
6   browser_tests                       0x000000010afe068d SystemURLRequestContextGetter::SystemURLRequestContextGetter(IOThread*) + 29
7   browser_tests                       0x000000010afe4ef1 scoped_refptr<SystemURLRequestContextGetter> base::MakeRefCounted<SystemURLRequestContextGetter, IOThread*>(IOThread*&&) + 65
8   browser_tests                       0x000000010afe4e10 IOThread::system_url_request_context_getter() + 336
9   browser_tests                       0x000000010ac7313d BrowserProcessImpl::system_request_context() + 221
10  browser_tests                       0x000000010f985718 safe_browsing::SafeBrowsingService::Initialize() + 264
11  browser_tests                       0x000000010ac7a20e BrowserProcessImpl::CreateSafeBrowsingService() + 270
12  browser_tests                       0x000000010ac7a0b2 BrowserProcessImpl::safe_browsing_service() + 226
13  browser_tests                       0x000000010adb11a6 ChromeContentBrowserClient::ResourceDispatcherHostCreated() + 294
14  libcontent.dylib                    0x000000012e95c03c content::BrowserMainLoop::BrowserThreadsStarted() + 10060
15  libcontent.dylib                    0x000000012e96419d int base::internal::FunctorTraits<int (content::BrowserMainLoop::*)(), void>::Invoke<content::BrowserMainLoop*>(int (content::BrowserMainLoop::*)(), content::BrowserMainLoop*&&) + 125
16  libcontent.dylib                    0x000000012e9640e4 int base::internal::InvokeHelper<false, int>::MakeItSo<int (content::BrowserMainLoop::* const&)(), content::BrowserMainLoop*>(int (content::BrowserMainLoop::* const&&&)(), content::BrowserMainLoop*&&) + 68
17  libcontent.dylib                    0x000000012e964073 int base::internal::Invoker<base::internal::BindState<int (content::BrowserMainLoop::*)(), base::internal::UnretainedWrapper<content::BrowserMainLoop> >, int ()>::RunImpl<int (content::BrowserMainLoop::* const&)(), std::__1::tuple<base::internal::UnretainedWrapper<content::BrowserMainLoop> > const&, 0ul>(int (content::BrowserMainLoop::* const&&&)(), std::__1::tuple<base::internal::UnretainedWrapper<content::BrowserMainLoop> > const&&&, std::__1::integer_sequence<unsigned long, 0ul>) + 99
18  libcontent.dylib                    0x000000012e963f7c base::internal::Invoker<base::internal::BindState<int (content::BrowserMainLoop::*)(), base::internal::UnretainedWrapper<content::BrowserMainLoop> >, int ()>::Run(base::internal::BindStateBase*) + 44
19  libcontent.dylib                    0x000000012fd9f4dd base::RepeatingCallback<int ()>::Run() const & + 61
20  libcontent.dylib                    0x000000012fd9f3b0 content::StartupTaskRunner::RunAllTasksNow() + 528
21  libcontent.dylib                    0x000000012e9585d4 content::BrowserMainLoop::CreateStartupTasks() + 2404
22  libcontent.dylib                    0x000000012e967336 content::BrowserMainRunnerImpl::Initialize(content::MainFunctionParams const&) + 2198
23  libcontent.dylib                    0x000000012e94ffba content::BrowserMain(content::MainFunctionParams const&) + 554
24  libcontent.dylib                    0x00000001315779eb content::RunNamedProcessTypeMain(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, content::MainFunctionParams const&, content::ContentMainDelegate*) + 603
25  libcontent.dylib                    0x0000000131579266 content::ContentMainRunnerImpl::Run() + 1334
26  libcontent.dylib                    0x000000013156fe35 content::ContentServiceManagerMainDelegate::RunEmbedderProcess() + 53
27  libembedder.dylib                   0x000000013f59f850 service_manager::Main(service_manager::MainParams const&) + 2128
28  libcontent.dylib                    0x000000013157774c content::ContentMain(content::ContentMainParams const&) + 92
29  browser_tests                       0x000000010c6f0961 content::BrowserTestBase::SetUp() + 8097
30  browser_tests                       0x000000010ab3b584 InProcessBrowserTest::SetUp() + 1972
31  browser_tests                       0x000000010793a43e ExtensionBrowserTest::SetUp() + 238
32  browser_tests                       0x000000010857b98e void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) + 126
33  browser_tests                       0x00000001085577b2 void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) + 114
34  browser_tests                       0x0000000108557694 testing::Test::Run() + 116
35  browser_tests                       0x00000001085586ad testing::TestInfo::Run() + 221
36  browser_tests                       0x0000000108559a7c testing::TestCase::Run() + 236
37  browser_tests                       0x0000000108566baa testing::internal::UnitTestImpl::RunAllTests() + 970
38  browser_tests                       0x000000010857e89e bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) + 126
39  browser_tests                       0x0000000108566762 bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) + 114
40  browser_tests                       0x000000010856663d testing::UnitTest::Run() + 397
41  browser_tests                       0x000000010ab94e41 RUN_ALL_TESTS() + 17
42  browser_tests                       0x000000010ab94190 base::TestSuite::Run() + 352
43  browser_tests                       0x000000010ab10672 ChromeTestSuiteRunner::RunTestSuite(int, char**) + 82
44  browser_tests                       0x000000010ab107f9 ChromeTestLauncherDelegate::RunTestSuite(int, char**) + 57
45  browser_tests                       0x000000010c7ff3d1 content::LaunchTests(content::TestLauncherDelegate*, unsigned long, int, char**) + 881
46  browser_tests                       0x000000010ab11dbb LaunchChromeTests(unsigned long, content::TestLauncherDelegate*, int, char**) + 1691
47  browser_tests                       0x000000010ab10539 main + 153
48  libdyld.dylib                       0x00007fff8ff555fd start + 1
49  ???                                 0x000000000000000a 0x0 + 10

[94452:40963:0208/183935.951814:FATAL:leak_tracker.h(106)] Check failed: 0u == count (0 vs. 1)
0   libbase.dylib                       0x00000001237fc28e base::debug::StackTrace::StackTrace(unsigned long) + 174
1   libbase.dylib                       0x00000001237fc34d base::debug::StackTrace::StackTrace(unsigned long) + 29
2   libbase.dylib                       0x00000001237fa7cc base::debug::StackTrace::StackTrace() + 28
3   libbase.dylib                       0x00000001238940df logging::LogMessage::~LogMessage() + 479
4   libbase.dylib                       0x0000000123891e15 logging::LogMessage::~LogMessage() + 21
5   browser_tests                       0x000000010afec76f base::debug::LeakTracker<SystemURLRequestContextGetter>::CheckForLeaks() + 687
6   browser_tests                       0x000000010afec10d IOThread::CleanUp() + 461
7   libcontent.dylib                    0x000000012e982e00 content::BrowserThreadImpl::CleanUp() + 144
8   libcontent.dylib                    0x000000012e97f485 content::BrowserProcessSubThread::CleanUp() + 69
9   libbase.dylib                       0x0000000123afb7ba base::Thread::ThreadMain() + 2602
10  libbase.dylib                       0x0000000123ad29ba base::(anonymous namespace)::ThreadFunc(void*) + 682
11  libsystem_pthread.dylib             0x00007fff93019899 _pthread_body + 138
12  libsystem_pthread.dylib             0x00007fff9301972a _pthread_struct_init + 0
13  libsystem_pthread.dylib             0x00007fff9301dfc9 thread_start + 13

[1/791] PlatformAppBrowserTest.AppWithContextMenuClicked (CRASHED)