In this build:
https://ci.chromium.org/buildbot/chromium.gpu.fyi/Win10%20Release%20%28Intel%20HD%20630%29/922

The test WebglConformance_conformance_glsl_misc_shader_with_non_reserved_words failed inside the webgl_conformance_d3d11_passthrough_tests test suite.

Here was the stack trace:

  	Last event: 20e8.1aa4: Break instruction exception - code 80000003 (first/second chance not available)
  	  debugger time: Mon Oct 30 07:50:59.150 2017 (UTC - 7:00)
  	ChildEBP RetAddr  Args to Child              
  	0073ce4c 6be493e9 6db88628 000000c1 091a1868 chrome_child!base::debug::BreakDebugger+0xc
  	0073ce74 6af316be 0525cb60 0073cec0 0073cec4 chrome_child!?Run@?$Invoker@U?$BindState@P6AXPBDHV?$BasicStringPiece@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@base@@1@Z$$V@internal@base@@$$A6AXPBDHV?$BasicStringPiece@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@3@1@Z@internal@base@@SAXPAVBindStateBase@23@$$QAPBD$$QAH$$QAV?$BasicStringPiece@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@3@3@Z+0x25
  	0073d308 6adaa927 00000003 0073d500 6d9ce174 chrome_child!logging::LogMessage::~LogMessage+0x41e
  	0073d3d8 6adb7831 09119df0 0006ab72 052d98b0 chrome_child!blink::ThreadHeap::CheckAndMarkPointer+0xdb
  	0073d3f4 6adac0bd 09119df0 6adba682 00000000 chrome_child!blink::ThreadState::VisitStack+0x2f
  	0073d4dc 6adbacee 09119df0 3c418938 41606287 chrome_child!blink::ThreadHeap::VisitStackRoots+0x77
  	0073d518 6adb7658 4569e3c0 6e63018c 8687dbd9 chrome_child!blink::ThreadState::MarkPhaseVisitRoots+0xa0
  	0073d64c 6adb88a1 00000001 00000001 00000002 chrome_child!blink::ThreadState::CollectGarbage+0xbc
  	0073d720 6adb31e0 00000008 456beff3 00000002 chrome_child!blink::ThreadState::ScheduleGCIfNeeded+0xf3
  	0073d7f0 6adb3368 00000050 00000049 0073d838 chrome_child!blink::NormalPageArena::OutOfLineAllocate+0x120
  	0073d8d0 6adc237b 00000050 00000049 00000050 chrome_child!blink::NormalPageArena::AllocateObject+0x136
  	0073d9b0 6c04f277 6e63018c 0000004c 0000000b chrome_child!blink::ThreadHeap::AllocateOnArenaIndex+0x10f
  	0073d9d8 6c1089c5 0000004c 00000000 29414e10 chrome_child!blink::Node::AllocateObject+0x35
  	0073dab0 6ce4d9ac 40304c48 00000000 0073dd10 chrome_child!blink::HTMLLIElement::Create+0x25
  	0073db84 6d19022b 0073db98 40304c48 00000000 chrome_child!blink::HTMLElementFactory::createHTMLElement+0xd8
  	0073dbc0 6ced78f1 0073dc18 0073dbf8 00000000 chrome_child!blink::Document::createElement+0x11b
  	0073dce0 39892cf6 0073dcf0 39889c13 0073dd10 chrome_child!blink::V8Document::createElementMethodCallbackForMainWorld+0x1af


Currently this is only a bug sighting but it's suspicious that the same test failed at the same time on a totally different bot (Mac Debug with NVIDIA GPU):
https://ci.chromium.org/buildbot/chromium.gpu.fyi/Mac%20Retina%20Debug%20%28NVIDIA%29/6688