Suppress deqp/functional/gles3/negativetextureapi.html

On Pixel 2 this test has begun consistently failing. Suppressing it
while the root cause is analyzed.

TBR=ynovikov@chromium.org
TEST= webgl2_conformance_tests
deqp/functional/gles3/negativetextureapi.html

Bug: 1027125
Change-Id: Ie727ed406c10b42cfab5fb8f999068de32c19810
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1928145Reviewed-by: Jonathan Ross <jonross@chromium.org>
Commit-Queue: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/master@{#717712}

content/test/gpu/gpu_tests/test_expectations/webgl2_conformance_expectations.txt

@@ -720,6 +720,7 @@ crbug.com/906735 [ android qualcomm ] conformance2/textures/video/tex-2d-rgba8ui
 crbug.com/981216 [ android qualcomm-adreno-(tm)-540 ] deqp/functional/gles3/fbocolorbuffer/tex2d_01.html [ RetryOnFailure ]
 crbug.com/949321 [ android qualcomm ] deqp/functional/gles3/framebufferblit/default_framebuffer_02.html [ RetryOnFailure ]
 crbug.com/1022410 [ android qualcomm ] conformance2/transform_feedback/switching-objects.html [ RetryOnFailure ]
+crbug.com/1027125 [ android qualcomm ] deqp/functional/gles3/negativetextureapi.html [ Failure ]
 
 # This test is failing on Android Pixel 2 and 3 (Qualcomm)
 # Seems to be an OpenGL ES bug.