Since this build:
https://ci.chromium.org/buildbot/chromium.gpu.fyi/Win7%20Release%20%28NVIDIA%29/31981

WebglConformance_conformance2_textures_canvas_sub_rectangle_tex_2d_rgb565_rgb_unsigned_byte has been failing reliably. The GPU process crashes, with this stack trace:

  Last event: 438.494: Break instruction exception - code 80000003 (first/second chance not available)
    debugger time: Sun Nov  5 19:43:42.175 2017 (UTC - 8:00)
  ChildEBP RetAddr  Args to Child              
  0038e5e4 672252db 69236aa0 00000114 02c58cd1 chrome_child!base::debug::BreakDebugger+0xc
  0038e60c 66300b0e 02c48b48 0038e658 0038e65c 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
  0038eaa0 66eb0b22 00000003 0038eab8 68d9f174 chrome_child!logging::LogMessage::~LogMessage+0x41e
  0038eb6c 66eb07b5 02c58828 68e0fb75 00000019 chrome_child!gl::GLContextEGL::IsCurrent+0xa8
  0038ec84 67fa5980 02c58828 02c50ab4 00db6ed8 chrome_child!gl::GLContextEGL::MakeCurrent+0x61
  0038ecc8 67faab99 02c50a20 08d7c780 0038ece4 chrome_child!gpu::GpuCommandBufferStub::Destroy+0x128
  0038ecd8 67faa607 02bc6ec0 0038ed00 67fa562e chrome_child!gpu::GpuCommandBufferStub::~GpuCommandBufferStub+0x47
  0038ece4 67fa562e 00000001 02bc6ed4 02bc6ec0 chrome_child!gpu::GpuCommandBufferStub::`scalar deleting destructor'+0xb
  0038ed00 67fa4aa7 02bc4fa4 0038ed24 67f9fe1e chrome_child!gpu::GpuChannel::~GpuChannel+0x34
  0038ed0c 67f9fe1e 00000001 02bc4fa0 02c4b040 chrome_child!gpu::GpuChannel::`scalar deleting destructor'+0xb
  0038ed24 67f9f63e 0038ed38 c3a0bda4 02bc4fa0 chrome_child!std::list<std::pair<int const ,std::unique_ptr<gpu::GpuChannel,std::default_delete<gpu::GpuChannel> > >,std::allocator<std::pair<int const ,std::unique_ptr<gpu::GpuChannel,std::default_delete<gpu::GpuChannel> > > > >::clear+0x2e
  0038ed3c 67f9f4dd 0038ed58 02c4b040 02bc4fa0 chrome_child!std::_Hash<std::_Umap_traits<int,std::unique_ptr<gpu::GpuChannel,std::default_delete<gpu::GpuChannel> >,std::_Uhash_compare<int,std::hash<int>,std::equal_to<int> >,std::allocator<std::pair<int const ,std::unique_ptr<gpu::GpuChannel,std::default_delete<gpu::GpuChannel> > > >,0> >::clear+0x1a
  0038ed50 670ef737 02bbbc58 0038ed50 0038ed50 chrome_child!gpu::GpuChannelManager::~GpuChannelManager+0xd
  0038ee40 670eaf0b 02bbdb84 0038ef20 6620e8a9 chrome_child!viz::GpuServiceImpl::~GpuServiceImpl+0x1f7
  0038ee4c 6620e8a9 00000001 7701321c 7624c739 chrome_child!viz::GpuServiceImpl::`scalar deleting destructor'+0xb
  0038ef20 67913948 02bcd128 c3a0bda4 02bbda68 chrome_child!viz::VizMainImpl::~VizMainImpl+0x115
  0038ef38 679141d3 0038f148 0038f018 67285f76 chrome_child!content::GpuChildThread::~GpuChildThread+0xec
  0038ef44 67285f76 00000001 69b40f90 66323eb2 chrome_child!content::GpuChildThread::`scalar deleting destructor'+0xb
  0038f018 67912dab 02badae0 01f98cdc 02b92700 chrome_child!content::ChildProcess::~ChildProcess+0xac
  0038f20c 662f481e 0038f2f8 02b9fe70 00000000 chrome_child!content::GpuMain+0x38f
  0038f2dc 662f4d86 0038f310 0038f2f8 0038f564 chrome_child!content::RunNamedProcessTypeMain+0x10a
  0038f3d8 662fa6eb 0038f328 00000003 0038f4f8 chrome_child!content::ContentMainRunnerImpl::Run+0x116
  0038f4e8 662f46ed 0038f4f4 0038f4f8 68f8bf30 chrome_child!service_manager::Main+0x2a3
  0038f528 653d1120 0038f54c 0038f534 0038f530 chrome_child!content::ContentMain+0x31
  *** WARNING: Unable to verify checksum for chrome.exe
  0038f598 009b53d4 009b0000 0038f5e0 3e18ea2c chrome_child!ChromeMain+0x120
  0038f624 009b154f 009b0000 3e18ea2c 00000004 chrome!MainDllLoader::Launch+0x22e
  0038f79c 00a94078 009b0000 00000000 00cc2958 chrome!wWinMain+0x54f
 

The main CL in that unfortunately large set of changes that seems related is https://chromium-review.googlesource.com/748106 , from Issue 769415. However, a revert of that CL has been tried and it didn't help. We need to debug this directly and perhaps try local reverts of CLs to figure out what's going wrong. In the meantime, suppressing the test failure to get the bot green again.

Note that this is somewhat related to the Quadro P400 upgrade from Issue 712469, but the test was passing immediately after the upgrade. It only started failing a couple of builds after the upgrade.