webgl2_conformance_tests on NVIDIA GPU on Windows (with patch) on Windows-10 failed in
https://ci.chromium.org/p/chromium/builders/luci.chromium.try/win-angle-rel/21
same patchset passed in
https://ci.chromium.org/p/chromium/builders/luci.chromium.try/win-angle-rel/33

[107/138] gpu_tests.webgl_conformance_integration_test.WebGLConformanceIntegrationTest.WebglConformance_deqp_functional_gles3_framebufferblit_depth_stencil failed unexpectedly 36.9150s:
  
  Traceback (most recent call last):
    _RunGpuTest at content\test\gpu\gpu_tests\gpu_integration_test.py:155
      self.RunActualGpuTest(url, *args)
    RunActualGpuTest at content\test\gpu\gpu_tests\webgl_conformance_integration_test.py:199
      getattr(self, test_name)(test_path, *args[1:])
    _RunConformanceTest at content\test\gpu\gpu_tests\webgl_conformance_integration_test.py:288
      self._CheckTestCompletion()
    _CheckTestCompletion at content\test\gpu\gpu_tests\webgl_conformance_integration_test.py:284
      self.fail(self._WebGLTestMessages(self.tab))
    fail at .swarming_module\bin\Lib\unittest\case.py:410
      raise self.failureException(msg)
  AssertionError: blit.depth_stencil.depth24_stencil8_depth_only: 
  Init testcase: blit.depth_stencil.depth_component32f_basic
  Init testcase: blit.depth_stencil.depth_component32f_scale
  Init testcase: blit.depth_stencil.depth_component24_basic
  Init testcase: blit.depth_stencil.depth_component24_scale
  Init testcase: blit.depth_stencil.depth_component16_basic
  Init testcase: blit.depth_stencil.depth_component16_scale
  Init testcase: blit.depth_stencil.depth32f_stencil8_basic
  Init testcase: blit.depth_stencil.depth32f_stencil8_scale
  Init testcase: blit.depth_stencil.depth32f_stencil8_depth_only
  Init testcase: blit.depth_stencil.depth32f_stencil8_stencil_only
  Init testcase: blit.depth_stencil.depth24_stencil8_basic
  Init testcase: blit.depth_stencil.depth24_stencil8_depth_only
  FAIL 
  Init testcase: blit.depth_stencil.stencil_index8_basic
  Init testcase: blit.depth_stencil.stencil_index8_scale

Will suppress.