Suppress 5 WebGL tests on Mac SwANGLE

Recent regressions.
conformance/reading/read-pixels-pack-alignment.html
conformance/rendering/clear-after-copyTexImage2D.html
conformance/rendering/gl-viewport-test.html
conformance/rendering/multisample-corruption.html
conformance/textures/misc/tex-image-canvas-corruption.html

TBR=bsheedy

Bug: swiftshader:154, 1123524
Change-Id: I0cb48304919cfe96065d1bfdecaa22fe5680babf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2385595Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803127}

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

@@ -794,9 +794,13 @@ crbug.com/1099978 [ mac swiftshader passthrough ] conformance/glsl/samplers/glsl
 crbug.com/1102991 [ mac swiftshader passthrough ] conformance/more/functions/copyTexSubImage2D.html [ RetryOnFailure ]
 crbug.com/1102991 [ mac swiftshader passthrough ] conformance/more/functions/deleteBufferBadArgs.html [ RetryOnFailure ]
 crbug.com/1102991 [ mac swiftshader passthrough ] conformance/more/glsl/uniformOutOfBounds.html [ RetryOnFailure ]
+crbug.com/1123524 [ mac swiftshader passthrough ] conformance/reading/read-pixels-pack-alignment.html [ Failure ]
 crbug.com/1099978 [ mac swiftshader passthrough ] conformance/reading/read-pixels-test.html [ Failure ]
 crbug.com/1099978 [ mac swiftshader passthrough ] conformance/renderbuffers/renderbuffer-initialization.html [ Failure ]
+crbug.com/1123524 [ mac swiftshader passthrough ] conformance/rendering/clear-after-copyTexImage2D.html [ Failure ]
 crbug.com/1099979 [ mac swiftshader passthrough ] conformance/rendering/draw-webgl-to-canvas-2d-repeatedly.html [ Failure ]
+crbug.com/1123524 [ mac swiftshader passthrough ] conformance/rendering/gl-viewport-test.html [ Failure ]
+crbug.com/1123524 [ mac swiftshader passthrough ] conformance/rendering/multisample-corruption.html [ Failure ]
 crbug.com/1099979 [ mac swiftshader passthrough ] conformance/textures/canvas/tex-2d-alpha-alpha-unsigned_byte.html [ Failure ]
 crbug.com/1099979 [ mac swiftshader passthrough ] conformance/textures/canvas/tex-2d-luminance_alpha-luminance_alpha-unsigned_byte.html [ Failure ]
 crbug.com/1099979 [ mac swiftshader passthrough ] conformance/textures/canvas/tex-2d-luminance-luminance-unsigned_byte.html [ Failure ]
@@ -820,6 +824,7 @@ crbug.com/1099979 [ mac swiftshader passthrough ] conformance/textures/image_bit
 crbug.com/1099979 [ mac swiftshader passthrough ] conformance/textures/image_bitmap_from_video/tex-2d-rgba-rgba-unsigned_short_5_5_5_1.html [ Failure ]
 crbug.com/1099979 [ mac swiftshader passthrough ] conformance/textures/misc/gl-pixelstorei.html [ Failure ]
 crbug.com/1102991 [ mac swiftshader passthrough ] conformance/textures/misc/tex-image-and-sub-image-2d-with-array-buffer-view.html [ RetryOnFailure ]
+crbug.com/swiftshader/154 [ mac swiftshader passthrough ] conformance/textures/misc/tex-image-canvas-corruption.html [ Failure ]
 crbug.com/1099979 [ mac swiftshader passthrough ] conformance/textures/misc/texparameter-test.html [ Failure ]
 crbug.com/1099979 [ mac swiftshader passthrough ] conformance/textures/misc/texture-corner-case-videos.html [ Failure ]
 crbug.com/1099979 [ mac swiftshader passthrough ] conformance/textures/misc/texture-npot-video.html [ Failure ]