Skip some WebGL tests on Nexus 5X

Skips the following tests on Nexus 5Xs w/ the validating decoder, as
they're flaking on the trybots and making FindIt unhappy despite already
having the RetryOnFailure expectation.

conformance/textures/canvas/tex-2d-rgba-rgba-unsigned_short_5_5_5_1.html
conformance/textures/canvas/tex-2d-alpha-alpha-unsigned_byte.html
conformance/textures/canvas/tex-2d-rgb-rgb-unsigned_short_5_6_5.html
conformance/textures/canvas/tex-2d-luminance-luminance-unsigned_byte.html
conformance/textures/canvas/tex-2d-luminance_alpha-luminance_alpha-unsigned_byte.html
conformance/textures/canvas/tex-2d-rgba-rgba-unsigned_short_4_4_4_4.html

TBR=kbr@chromium.org

Bug: 1095679
Change-Id: I810be0f879136bec193627237ed13e26b8c51b42
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2468566Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816806}

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

@@ -592,14 +592,14 @@ crbug.com/1043431 [ android qualcomm-adreno-(tm)-418 ] conformance/limits/gl-max
 crbug.com/951628 [ android qualcomm-adreno-(tm)-418 no-passthrough no-swiftshader-gl ] conformance/rendering/blending.html [ Failure ]
 crbug.com/1083320 [ android qualcomm-adreno-(tm)-418 ] conformance/misc/uninitialized-test.html [ Skip ]
 crbug.com/1056830 [ android qualcomm-adreno-(tm)-418 ] conformance/extensions/webgl-compressed-texture-astc.html [ Failure ]
-crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-alpha-alpha-unsigned_byte.html [ RetryOnFailure ]
-crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-luminance-luminance-unsigned_byte.html [ RetryOnFailure ]
-crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-luminance_alpha-luminance_alpha-unsigned_byte.html [ RetryOnFailure ]
+crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-alpha-alpha-unsigned_byte.html [ Skip ]
+crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-luminance-luminance-unsigned_byte.html [ Skip ]
+crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-luminance_alpha-luminance_alpha-unsigned_byte.html [ Skip ]
 crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-rgb-rgb-unsigned_byte.html [ RetryOnFailure ]
-crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-rgb-rgb-unsigned_short_5_6_5.html [ RetryOnFailure ]
+crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-rgb-rgb-unsigned_short_5_6_5.html [ Skip ]
 crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-rgba-rgba-unsigned_byte.html [ RetryOnFailure ]
-crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-rgba-rgba-unsigned_short_4_4_4_4.html [ RetryOnFailure ]
-crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-rgba-rgba-unsigned_short_5_5_5_1.html [ RetryOnFailure ]
+crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-rgba-rgba-unsigned_short_4_4_4_4.html [ Skip ]
+crbug.com/1095679 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/canvas/tex-2d-rgba-rgba-unsigned_short_5_5_5_1.html [ Skip ]
 crbug.com/1135785 [ android qualcomm-adreno-(tm)-418 no-passthrough ] conformance/textures/misc/texture-video-transparent.html [ RetryOnFailure ]
 # Timing out on this device for unknown reasons.
 crbug.com/1099148 [ android qualcomm-adreno-(tm)-418 ] deqp/data/gles2/shaders/swizzles.html [ Skip ]