Intermittent failure in /_webgl/conformance/misc/delayed-drawing.html

[jdm]

  ▶ Unexpected subtest result in /_webgl/conformance/misc/delayed-drawing.html:
  │ FAIL [expected PASS] WebGL test #6: draw should be 0, 192, 128, 255\nat (0, 0) expected: 0,192,128,255 was 0,0,0,0
  │   → assert_true: draw should be 0, 192, 128, 255
  │   → at (0, 0) expected: 0,192,128,255 was 0,0,0,0 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:1975:25
  │ 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
  │ checkCanvasRect/<@http://web-platform.test:8000/_webgl/js/webgl-test-utils.js:1269:19
  │ checkCanvasRectColor@http://web-platform.test:8000/_webgl/js/webgl-test-utils.js:1225:20
  │ checkCanvasRect@http://web-platform.test:8000/_webgl/js/webgl-test-utils.js:1257:23
  │ checkCanvas@http://web-platform.test:8000/_webgl/js/webgl-test-utils.js:1287:18
  │ drawAndCheck@http://web-platform.test:8000/_webgl/conformance/misc/delayed-drawing.html:78:7
  └ step2@http://web-platform.test:8000/_webgl/conformance/misc/delayed-drawing.html:70:3