Mark conformance2/rendering/attrib-type-match.html as Failing on OpenGL.

This test is flaky but occasionally hits the retry limit, mark as always
failing.

TBR=zmo@chromium.org
NOTRY=true

BUG=814905

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: Id0bcf0a33434008efebafeaed41cead9c21252c0
Reviewed-on: https://chromium-review.googlesource.com/1191025
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586751}

content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

@@ -373,7 +373,7 @@ class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
         ['passthrough', 'opengl'], bug=795030)
     self.Fail('deqp/functional/gles3/shaderpackingfunction.html',
         ['passthrough', 'opengl'], bug=794341)
-    self.Flaky('conformance2/rendering/attrib-type-match.html',
+    self.Fail('conformance2/rendering/attrib-type-match.html',
         ['passthrough', 'opengl'], bug=814905)
 
     # Passthrough command decoder / OpenGL / Windows