I followed the steps here:
https://www.chromium.org/developers/testing/webgl-conformance-tests

debug build from top of tree: 8f265dbe451806797bde728047fad52525e89d65
compiling with GOMA, no other GYP flags.

I've yet to find a single WebGL conformance test that will actually run. I have no problems on OS X. An error typically looks like this:

"""
D:\projects\chromium\src>python .\content\test\gpu\run_gpu_test.py webgl_conformance --story-filter=conformance_more_functions
(WARNING) 2016-03-18 18:25:34,239 desktop_browser_finder.FindAllAvailableBrowsers:148  Chrome build location for win_AMD64 not found. Browser will be run withou
t Flash.
(WARNING) 2016-03-18 18:25:34,239 browser_finder.FindBrowser:82  --browser omitted. Using most recent local build: debug
D:\projects\chromium\src\third_party\catapult\telemetry\telemetry\internal\results\results_options.py:144: UserWarning: Class BuildbotOutputFormatter is depreca
ted. It will no longer be supported on February 29, 2016. Please remove it or switch to an alternative before that time. Chart JSON is a supported alternative.
See https://goo.gl/8daFav .

  sys.stdout, trace_tag=options.output_trace_tag))
(WARNING) 2016-03-18 18:25:34,301 desktop_browser_finder.FindAllAvailableBrowsers:148  Chrome build location for win_AMD64 not found. Browser will be run withou
t Flash.
(WARNING) 2016-03-18 18:25:34,301 browser_finder.FindBrowser:82  --browser omitted. Using most recent local build: debug
[ RUN      ] WebglConformance.conformance_more_functions_bindBuffer
Traceback (most recent call last):
  File "D:\projects\chromium\src\third_party\catapult\telemetry\telemetry\internal\story_runner.py", line 84, in _RunStoryAndProcessErrorIfNeeded
    state.RunStory(results)
  File "D:\projects\chromium\src\content\test\gpu\gpu_tests\gpu_test_base.py", line 122, in RunStory
    RunStoryWithRetries(DesktopGpuSharedPageState, self, results)
  File "D:\projects\chromium\src\content\test\gpu\gpu_tests\gpu_test_base.py", line 72, in RunStoryWithRetries
    super(cls, shared_page_state).RunStory(results)
  File "D:\projects\chromium\src\third_party\catapult\telemetry\telemetry\page\shared_page_state.py", line 331, in RunStory
    self._current_page, self._current_tab, results)
  File "D:\projects\chromium\src\content\test\gpu\gpu_tests\webgl_conformance.py", line 78, in ValidateAndMeasurePage
    raise page_test.Failure(_WebGLTestMessages(tab))
Failure: TypeError: gl.createBuffer is not a function
testBindBufferARRAY_BUFFER
TypeError: gl.createBuffer is not a function
testBindBufferELEMENT_ARRAY_BUFFER
"""

I'm guessing I'm missing some obvious configuration that isn't described on the wiki?