Link to the first failure:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac%20FYI%20Retina%20Debug%20%28NVIDIA%29/2964


Log:
[5460:775:0801/182213.390894:ERROR:gles2_cmd_decoder.cc(9532)] [.WebGL-0x7fb259036000]GL ERROR :GL_INVALID_OPERATION : glUniform1fv: wrong uniform function for type
[5460:775:0801/182213.396528:ERROR:gles2_cmd_decoder.cc(9532)] [.WebGL-0x7fb259036000]GL ERROR :GL_INVALID_OPERATION : glUniform1fv: wrong uniform function for type
[5455:775:0801/182213.791607:INFO:CONSOLE(0)] "[.WebGL-0x7fb259036000]GL ERROR :GL_INVALID_OPERATION : glUniform1fv: wrong uniform function for type", source: http://127.0.0.1:51380/third_party/webgl/src/sdk/tests/conformance/uniforms/uniform-samplers-test.html (0)
[5455:775:0801/182213.795935:INFO:CONSOLE(0)] "[.WebGL-0x7fb259036000]GL ERROR :GL_INVALID_OPERATION : glUniform1fv: wrong uniform function for type", source: http://127.0.0.1:51380/third_party/webgl/src/sdk/tests/conformance/uniforms/uniform-samplers-test.html (0)
[5460:775:0801/182214.012521:ERROR:gles2_cmd_decoder.cc(9592)] [.WebGL-0x7fb259036000]GL ERROR :GL_INVALID_VALUE : glUniform1i: texture unit out of range
[5460:775:0801/182214.015657:ERROR:gles2_cmd_decoder.cc(9592)] [.WebGL-0x7fb259036000]GL ERROR :GL_INVALID_VALUE : glUniform1i: texture unit out of range
[5460:775:0801/182214.772806:ERROR:logger.cc(47)] Too many GL errors, not reporting any more for this context. use --disable-gl-error-limit to see all errors.
[5455:775:0801/182224.079033:INFO:CONSOLE(0)] "[.WebGL-0x7fb259036000]GL ERROR :GL_INVALID_VALUE : glUniform1i: texture unit out of range", source: http://127.0.0.1:51380/third_party/webgl/src/sdk/tests/conformance/uniforms/uniform-samplers-test.html (0)
[5455:775:0801/182224.083371:INFO:CONSOLE(0)] "[.WebGL-0x7fb259036000]GL ERROR :GL_INVALID_VALUE : glUniform1i: texture unit out of range", source: http://127.0.0.1:51380/third_party/webgl/src/sdk/tests/conformance/uniforms/uniform-samplers-test.html (0)
[5455:775:0801/182225.001877:INFO:CONSOLE(0)] "[.WebGL-0x7fb259036000]GL ERROR :GL_INVALID_VALUE : glUniform1i: texture unit out of range", source: http://127.0.0.1:51380/third_party/webgl/src/sdk/tests/conformance/uniforms/uniform-samplers-test.html (0)
[5455:775:0801/182225.006175:INFO:CONSOLE(0)] "[.WebGL-0x7fb259036000]GL ERROR :GL_INVALID_VALUE : glUniform1i: texture unit out of range", source: 
[5455:775:0801/182225.174714:INFO:CONSOLE(0)] "WebGL: too many errors, no more errors will be reported to the console for this context.", source: http://127.0.0.1:51380/third_party/webgl/src/sdk/tests/conformance/uniforms/uniform-samplers-test.html (0)

Traceback (most recent call last):
  _RunGpuTest at content/test/gpu/gpu_tests/gpu_integration_test.py:138
    self.RunActualGpuTest(url, *args)
  RunActualGpuTest at content/test/gpu/gpu_tests/webgl_conformance_integration_test.py:186
    getattr(self, test_name)(test_path, *args[1:])
  _RunConformanceTest at content/test/gpu/gpu_tests/webgl_conformance_integration_test.py:200
    self._CheckTestCompletion()
  _CheckTestCompletion at content/test/gpu/gpu_tests/webgl_conformance_integration_test.py:194
    'webglTestHarness._finished', timeout=self._GetTestTimeout())
  traced_function at third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py:52
    return func(*args, **kwargs)
  WaitForJavaScriptCondition at third_party/catapult/telemetry/telemetry/internal/actions/action_runner.py:261
    return self._tab.WaitForJavaScriptCondition(*args, **kwargs)
  traced_function at third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py:52
    return func(*args, **kwargs)
  WaitForJavaScriptCondition at third_party/catapult/telemetry/telemetry/internal/browser/web_contents.py:239
    return self._inspector_backend.WaitForJavaScriptCondition(*args, **kwargs)
  traced_function at third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py:52
    return func(*args, **kwargs)
  WaitForJavaScriptCondition at third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py:302
    e.message + '\n' + debug_message)
TimeoutException: Timed out while waiting 300s for IsJavaScriptExpressionTrue.
Console output:

Locals:
  IsJavaScriptExpressionTrue : <function IsJavaScriptExpressionTrue at 0x113c0e488>
  condition                  : 'webglTestHarness._finished'
  context_id                 : None
  debug_message              : 'Console output:\n'
  e                          : TimeoutException('Timed out while waiting 300s for IsJavaScriptExpressionTrue.',)
  kwargs                     : {}
  timeout                    : 300


Found crashpad_database_util
No minidump found via crashpad_database_util
Restarting browser due to unexpected test failure
Closing browser (pid=5455) ...
[5455:12291:0801/182740.703342:WARNING:discardable_shared_memory_manager.cc(431)] Some MojoDiscardableSharedMemoryManagerImpls are still alive. They will be leaked.
[5455:775:0801/182740.960947:WARNING:pref_notifier_impl.cc(23)] Pref observer found at shutdown.
[5455:775:0801/182740.961122:WARNING:pref_notifier_impl.cc(23)] Pref observer found at shutdown.
Browser is closed.
Starting Chrome ['/b/s/w/ir/out/Debug/Chromium.app/Contents/MacOS/Chromium', '--disable-gpu-watchdog', '--enable-experimental-web-platform-features', '--test-type=gpu', '--disable-gpu-process-for-dx12-vulkan-info-collection', '--disable-domain-blocking-for-3d-apis', '--disable-gpu-process-crash-limit', '--disable-blink-features=WebXR', '--js-flags=--expose-gc', '--enable-logging=stderr', '--autoplay-policy=no-user-gesture-required', '--disable-features=UseSurfaceLayerForVideo', '--enable-net-benchmarking', '--metrics-recording-only', '--no-default-browser-check', '--no-first-run', '--enable-gpu-benchmarking', '--deny-permission-prompts', '--autoplay-policy=no-user-gesture-required', '--disable-background-networking', '--disable-component-extensions-with-background-pages', '--disable-default-apps', '--disable-search-geolocation-disclosure', '--proxy-server=socks://localhost:51362', '--ignore-certificate-errors-spki-list=PhrPvGIaAMmd29hj8BCZOq096yj7uMpRNHpn5PDxI6I=', '--remote-debugging-port=0', '--enable-crash-reporter-for-testing', '--disable-component-update', '--window-size=1280,1024', '--user-data-dir=/b/s/w/itXkUo3I/tmpkJrG48', 'about:blank']

DevTools listening on ws://127.0.0.1:51653/devtools/browser/6b5bdf50-22e5-47fd-a26f-c523ad24f9b5
DoNothingForwarder started between 127.0.0.1:51653 and 51653
[5606:775:0801/182747.539869:WARNING:gaia_auth_fetcher.cc(924)] Could not reach Google Accounts servers: errno -120
Browser started (pid=5606).
OS: mac highsierra
Detailed OS version: 10.13.5 17F77
Model: MacBookPro 11.3
Browser command line: /b/s/w/ir/out/Debug/Chromium.app/Contents/MacOS/Chromium --disable-gpu-watchdog --enable-experimental-web-platform-features --test-type=gpu --disable-gpu-process-for-dx12-vulkan-info-collection --disable-domain-blocking-for-3d-apis --disable-gpu-process-crash-limit --disable-blink-features=WebXR --js-flags=--expose-gc --enable-logging=stderr --autoplay-policy=no-user-gesture-required --disable-features=UseSurfaceLayerForVideo --enable-net-benchmarking --metrics-recording-only --no-default-browser-check --no-first-run --enable-gpu-benchmarking --deny-permission-prompts --autoplay-policy=no-user-gesture-required --disable-background-networking --disable-component-extensions-with-background-pages --disable-default-apps --disable-search-geolocation-disclosure --proxy-server=socks://localhost:51362 --ignore-certificate-errors-spki-list=PhrPvGIaAMmd29hj8BCZOq096yj7uMpRNHpn5PDxI6I= --remote-debugging-port=0 --enable-crash-reporter-for-testing --disable-component-update --window-size=1280,1024 --user-data-dir=/b/s/w/itXkUo3I/tmpkJrG48 --flag-switches-begin --flag-switches-end about:blank
GPU device 0: VENDOR = 0x10de (Nvidia), DEVICE = 0xfe9
GPU device 1: VENDOR = 0x8086 (Intel), DEVICE = 0xd26
GPU Attributes:
  amd_switchable      : False
  can_support_threaded_texture_mailbox: False
  direct_rendering    : True
  encrypted_only      : False
  gl_extensions       : GL_ARB_blend_func_extended GL_ARB_draw_buffers_blend GL_ARB_draw_indirect GL_ARB_ES2_compatibility GL_ARB_explicit_attrib_location GL_ARB_gpu_shader_fp64 GL_ARB_gpu_shader5 GL_ARB_instanced_arrays GL_ARB_internalformat_query GL_ARB_occlusion_query2 GL_ARB_sample_shading GL_ARB_sampler_objects GL_ARB_separate_shader_objects GL_ARB_shader_bit_encoding GL_ARB_shader_subroutine GL_ARB_shading_language_include GL_ARB_tessellation_shader GL_ARB_texture_buffer_object_rgb32 GL_ARB_texture_cube_map_array GL_ARB_texture_gather GL_ARB_texture_query_lod GL_ARB_texture_rgb10_a2ui GL_ARB_texture_storage GL_ARB_texture_swizzle GL_ARB_timer_query GL_ARB_transform_feedback2 GL_ARB_transform_feedback3 GL_ARB_vertex_attrib_64bit GL_ARB_vertex_type_2_10_10_10_rev GL_ARB_viewport_array GL_EXT_debug_label GL_EXT_debug_marker GL_EXT_framebuffer_multisample_blit_scaled GL_EXT_texture_compression_s3tc GL_EXT_texture_filter_anisotropic GL_EXT_texture_sRGB_decode GL_APPLE_client_storage GL_APPLE_container_object_shareable GL_APPLE_flush_render GL_APPLE_object_purgeable GL_APPLE_rgb_422 GL_APPLE_row_bytes GL_APPLE_texture_range GL_ATI_texture_mirror_once GL_NV_texture_barrier
  gl_renderer         : Intel Iris Pro OpenGL Engine
  gl_reset_notification_strategy: 0
  gl_vendor           : Intel Inc.
  gl_version          : 4.1 INTEL-10.34.27
  gl_ws_extensions    : 
  gl_ws_vendor        : 
  gl_ws_version       : 
  in_process_gpu      : False
  initialization_time : 0.926396
  jpeg_decode_accelerator_supported: False
  max_framerate_denominator: 1
  max_framerate_numerator: 30
  max_msaa_samples    : 8
  max_resolution_height: 2160
  max_resolution_width: 4096
  min_resolution_height: 16
  min_resolution_width: 16
  oop_rasterization_supported: True
  optimus             : True
  passthrough_cmd_decoder: False
  pixel_shader_version: 4.10
  process_crash_count : 0
  profile             : 3
  sandboxed           : True
  software_rendering  : False
  vertex_shader_version: 4.10
  video_decode_accelerator_flags: 0
Feature Status:
  2d_canvas           : enabled
  flash_3d            : enabled
  flash_stage3d       : enabled
  flash_stage3d_baseline: enabled
  gpu_compositing     : enabled
  multiple_raster_threads: enabled_on
  native_gpu_memory_buffers: enabled
  oop_rasterization   : disabled_off
  protected_video_decode: unavailable_off
  rasterization       : enabled
  skia_deferred_display_list: disabled_off
  skia_renderer       : disabled_off
  surface_synchronization: enabled_on
  video_decode        : enabled
  viz_display_compositor: disabled_off
  webgl               : enabled
  webgl2              : enabled
Driver Bug Workarounds:
  add_and_true_to_loop_condition
  adjust_src_dst_region_for_blitframebuffer
  avoid_stencil_buffers
  decode_encode_srgb_for_generatemipmap
  disable_2d_canvas_auto_flush
  disable_framebuffer_cmaa
  disable_webgl_rgb_multisampling_usage
  dont_use_loops_to_initialize_variables
  emulate_abs_int_function
  get_frag_data_info_bug
  init_two_cube_map_levels_before_copyteximage
  msaa_is_slow
  pack_parameters_workaround_with_pack_buffer
  rebind_transform_feedback_before_resume
  regenerate_struct_names
  remove_invariant_and_centroid_for_essl3
  reset_teximage2d_base_level
  rewrite_texelfetchoffset_to_texelfetch
  scalarize_vec_and_mat_constructor_args
  set_zero_level_before_generating_mipmap
  unfold_short_circuit_as_ternary_operation
  unpack_alignment_workaround_with_unpack_buffer
  unpack_image_height_workaround_with_unpack_buffer
  use_intermediary_for_copy_texture_image
  use_unused_standard_shared_blocks
  disabled_extension__gl__khr_blend_equation_advanced
  disabled_extension__gl__khr_blend_equation_advanced_coherent
[5611:775:0801/182747.961998:WARNING:ca_layer_tree_coordinator.mm(55)] Blank frame: No overlays or CALayers
[5606:775:0801/182748.515834:WARNING:gaia_auth_fetcher.cc(924)] Could not reach Google Accounts servers: errno -120
[419/462] gpu_tests.webgl_conformance_integration_test.WebGLConformanceIntegrationTest.WebglConformance_conformance_uniforms_uniform_samplers_test failed unexpectedly 335.6890s:
  
  Traceback (most recent call last):
    _RunGpuTest at content/test/gpu/gpu_tests/gpu_integration_test.py:138
      self.RunActualGpuTest(url, *args)
    RunActualGpuTest at content/test/gpu/gpu_tests/webgl_conformance_integration_test.py:186
      getattr(self, test_name)(test_path, *args[1:])
    _RunConformanceTest at content/test/gpu/gpu_tests/webgl_conformance_integration_test.py:200
      self._CheckTestCompletion()
    _CheckTestCompletion at content/test/gpu/gpu_tests/webgl_conformance_integration_test.py:194
      'webglTestHarness._finished', timeout=self._GetTestTimeout())
    traced_function at third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py:52
      return func(*args, **kwargs)
    WaitForJavaScriptCondition at third_party/catapult/telemetry/telemetry/internal/actions/action_runner.py:261
      return self._tab.WaitForJavaScriptCondition(*args, **kwargs)
    traced_function at third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py:52
      return func(*args, **kwargs)
    WaitForJavaScriptCondition at third_party/catapult/telemetry/telemetry/internal/browser/web_contents.py:239
      return self._inspector_backend.WaitForJavaScriptCondition(*args, **kwargs)
    traced_function at third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py:52
      return func(*args, **kwargs)
    WaitForJavaScriptCondition at third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py:302
      e.message + '\n' + debug_message)
  TimeoutException: Timed out while waiting 300s for IsJavaScriptExpressionTrue.
  Console output:
  
  Locals:
    IsJavaScriptExpressionTrue : <function IsJavaScriptExpressionTrue at 0x113c0e488>
    condition                  : 'webglTestHarness._finished'
    context_id                 : None
    debug_message              : 'Console output:\n'
    e                          : TimeoutException('Timed out while waiting 300s for IsJavaScriptExpressionTrue.',)
    kwargs                     : {}
    timeout                    : 300