Intermittent failure in /_webgl/conformance/textures/misc/tex-sub-image-2d.html

[jdm]

 ▶ Unexpected subtest result in /_webgl/conformance/textures/misc/tex-sub-image-2d.html:
  │ FAIL [expected PASS] WebGL test #0: pixel at (1, 0) was (0, 0, 0), should be (1, 1, 1)
  │   → assert_true: pixel at (1, 0) was (0, 0, 0), should be (1, 1, 1) expected true got false
  │ 
  │ reportTestResultsToHarness/<@http://web-platform.test:8000/_webgl/js/js-test-pre.js:123:24
  │ Test.prototype.step@http://web-platform.test:8000/resources/testharness.js:1988:25
  │ test@http://web-platform.test:8000/resources/testharness.js:535:30
  │ reportTestResultsToHarness@http://web-platform.test:8000/_webgl/js/js-test-pre.js:122:15
  │ testFailed@http://web-platform.test:8000/_webgl/js/js-test-pre.js:249:31
  └ @http://web-platform.test:8000/_webgl/conformance/textures/misc/tex-sub-image-2d.html:107:19