Is there a bisect range for this flake appearing?

This test has been running for two weeks and this is the first flake report I've received. So this might be detecting an actual bug.

That was the only run where I saw the test fail.  Now there are 2 new failures:

IsolatedOriginTest.ProcessLimit
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65317

SitePerProcessBrowserTest.NavigateRemoteFrame
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65357

jonross@ it's clear now that these are not specific flaky tests, but there is something systematic going on.  It's not good to have these tests flaking on the CQ and potentially blocking devs from landing CLs.  Is there anything I can do to help debug the issue?

These are the first reports I've had of these tests failing.

The FYI bot we're running, which is behind the CQ, has not shown these failures yet.

A bisect range would help find the source of the bug.

The earliest flake I see is IsolatedOriginTest.ProcessLimit at https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/64838
which was on 2017-11-22.  There are no other flakes on viz_content_browsertests for several hundred builds thereafter.

But since the flake is unreliable to reproduce, the regression probably didn't come from a CL on that run, but probably from one that landed a bit earlier.  I would start by taking a look at some of these:

$ git log --pretty=oneline 420aa00b86f48a73f4de759049fec08a73f04d59 -- components/viz services/viz
155d3c94d1fe7d80e7c486c0b358b723fd832f8f Migrate viz::SingleReleaseCallback to OnceCallback
7865b5be0f6472b14ed7a30bc7e41896a8ec9e6e cc: Replace SkImageFilter with PaintFilter in paint recordings.
ee41ffee3151b23dfe5a9e25b2ffe0d8a255b6a1 cc: Run threaded LayerTreeTests with sync scheduling.
b6dfa716e50ee4243a78390e4405e7ec54bc9ea5 Fix CompositorFrameSinkSupport::GetSurfaceSize().
d9f6e099e9c7b3ab4dfa182e32adc0ae2599f63f jda: move files from media/gpu to media/mojo
58c07c7bdf1b9c9d0ebc853e96342f3376d875bf Initialize color_buffer_half_float_rgba in passthrough
2d06761bccd6a06fd114298646cec6360b5b1995 Remove YUVVideoDrawQuad::ColorSpace
366872053d5da2a353f4eeff12d5c4e87dc7d73b move and rename GpuJpegDecodeAcceleratorFactoryProvider
e3d0e8751ff6a65a0d5aaae3b9cefd254e95d3e8 Fix task runner usage in GLRenderer and rename TextureMailboxDeleter.
afc2fea94f3cb386c8e606d4f9320248c84d5ef8 Optimize Draw Occlusion algorithm
625e74db3a50b8e60ac9da09c15e5fe41bc620d4 viz: Fix TRACE_EVENTS labels.
df6ab1a91ea1450495fb2a3f5f4993deb5cc33fc Surface synchronization: Add some useful trace events
83f870d952cba7f1183f44b3d8bf149137a95acb Surface synchronization: GarbageCollectSurfaces at end of frame
6b082cc1f608071048b890e9422401c19778240e Remove TextureMailbox resources from ResourceProvider
5df8257fa86cd90614aa6d9f0825a3640e15d062 Pass TransferableResource through TextureLayer
a576e5a42af0eb0e4cc140ddfdda40101d1c727d Remove dead code for the old video detector
417f0cf7506bf91c82b9e75b0036a2b41ff5b549 mus: Enable arc video accelerators in viz
14e8a9bb81b244d39909a0f5897489fed3652365 viz: Add IPC to set authoritative vsync inteval.
feaa47c68a99a0817c2b945801fdc9d2873fc6b6 gpu: Remove gpu's dependency on ui/latency_info.

Thanks for the range and looking into this.

I'll triage and we'll debug from there.

 Issue 792740  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9e593546c4186256c858e5e786bd51fa76a51dbd

commit 9e593546c4186256c858e5e786bd51fa76a51dbd
Author: Tom Anderson <thomasanderson@chromium.org>
Date: Thu Dec 07 20:03:50 2017

Disable flaky tests on viz

BUG= 792739 , 792740 
R=jonross@chromium.org

Change-Id: I0b4a38acf3cf9ee0dbd55ed5453b13ae2988834b
Reviewed-on: https://chromium-review.googlesource.com/813114
Commit-Queue: Jonathan Ross <jonross@chromium.org>
Reviewed-by: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522521}
[modify] https://crrev.com/9e593546c4186256c858e5e786bd51fa76a51dbd/testing/buildbot/filters/mojo.fyi.viz.content_browsertests.filter
[modify] https://crrev.com/9e593546c4186256c858e5e786bd51fa76a51dbd/testing/buildbot/filters/viz.content_browsertests.filter

Also SitePerProcessBrowserTest.RFPHDestruction

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8bf911dc3962c0301a5f3d0c9dc72242e9337c68

commit 8bf911dc3962c0301a5f3d0c9dc72242e9337c68
Author: Tom Anderson <thomasanderson@chromium.org>
Date: Thu Dec 14 15:23:11 2017

Disable SitePerProcessBrowserTest.RFPHDestruction on viz

Failing runs on Linux Tests:
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65554
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65557

BUG= 792739 
R=jonross@chromium.org

Change-Id: I7e1c151f5eaa108c4416a681d22d26884493ec6a
Reviewed-on: https://chromium-review.googlesource.com/826462
Commit-Queue: Jonathan Ross <jonross@chromium.org>
Reviewed-by: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524069}
[modify] https://crrev.com/8bf911dc3962c0301a5f3d0c9dc72242e9337c68/testing/buildbot/filters/mojo.fyi.viz.content_browsertests.filter
[modify] https://crrev.com/8bf911dc3962c0301a5f3d0c9dc72242e9337c68/testing/buildbot/filters/viz.content_browsertests.filter

Stack trace of error:

BrowserTestBase received signal: Segmentation fault. Backtrace:
#0 0x000002c87eac base::debug::StackTrace::StackTrace()
#1 0x0000029eb3c2 content::(anonymous namespace)::DumpStackTraceSignalHandler()
#2 0x7f2bb4b1bcb0 <unknown>
#3 0x00000274a967 content::RenderWidgetHostViewChildFrame::SendSurfaceInfoToEmbedderImpl()
#4 0x00000274b5a8 content::RenderWidgetHostViewChildFrame::OnFirstSurfaceActivation()
#5 0x000003c76527 viz::HostFrameSinkManager::OnFirstSurfaceActivation()
#6 0x000001b1f676 viz::mojom::FrameSinkManagerClientStubDispatch::Accept()
#7 0x000002aaaca7 mojo::internal::MultiplexRouter::ProcessIncomingMessage()
#8 0x000002aaa4db mojo::internal::MultiplexRouter::Accept()
#9 0x000002aa2232 mojo::Connector::ReadSingleMessage()
#10 0x000002aa2961 mojo::Connector::ReadAllAvailableMessages()
#11 0x0000031c6fca mojo::SimpleWatcher::OnHandleReady()
#12 0x000002c8921f base::debug::TaskAnnotator::RunTask()
#13 0x000002ca2c47 base::MessageLoop::RunTask()
#14 0x000002ca3168 base::MessageLoop::DoWork()
#15 0x000002ca578f base::(anonymous namespace)::WorkSourceDispatch()
#16 0x7f2bb8bd7e04 g_main_context_dispatch
#17 0x7f2bb8bd8048 <unknown>
#18 0x7f2bb8bd80ec g_main_context_iteration
#19 0x000002ca5652 base::MessagePumpGlib::Run()
#20 0x000002cbf804 base::RunLoop::Run()
#21 0x000002a0507e content::MessageLoopRunner::Run()
#22 0x0000029ebeb0 content::NavigateIframeToURL()
#23 0x00000151c055 content::SitePerProcessBrowserTest_CrossSiteIframeBlockedByXFrameOptionsOrCSP_Test::RunTestOnMainThread()
#24 0x0000029eb0ec content::BrowserTestBase::ProxyRunTestOnMainThreadLoop()
#25 0x000002a5e689 content::ShellBrowserMainParts::PreMainMessageLoopRun()
#26 0x0000024ad351 content::BrowserMainLoop::PreMainMessageLoopRun()
#27 0x0000027e4e27 content::StartupTaskRunner::RunAllTasksNow()
#28 0x0000024ab9bc content::BrowserMainLoop::CreateStartupTasks()
#29 0x0000024b0618 content::BrowserMainRunnerImpl::Initialize()
#30 0x000002a5df09 ShellBrowserMain()
#31 0x000002a28b00 content::ShellMainDelegate::RunProcess()
#32 0x0000023eebc0 content::RunNamedProcessTypeMain()
#33 0x0000023ef5d5 content::ContentMainRunnerImpl::Run()
#34 0x000003d68c9f service_manager::Main()
#35 0x000001bc10e1 content::ContentMain()
#36 0x0000029ead8e content::BrowserTestBase::SetUp()
#37 0x0000029e180e content::ContentBrowserTest::SetUp()
#38 0x00000172f301 testing::Test::Run()
#39 0x00000172fd70 testing::TestInfo::Run()
#40 0x000001730257 testing::TestCase::Run()
#41 0x000001736887 testing::internal::UnitTestImpl::RunAllTests()
#42 0x000001736507 testing::UnitTest::Run()
#43 0x000002a138e2 base::TestSuite::Run()
#44 0x0000029e5167 content::ContentTestLauncherDelegate::RunTestSuite()
#45 0x0000029ff389 content::LaunchTests()
#46 0x0000029e5120 main
#47 0x7f2bb4b06f45 __libc_start_main
#48 0x0000010f602a _start

I think that this is  issue 797801  which has since been fixed. I'll test this on the FYI bot to confirm.