Suppress WebGL conformance flakes on Win/AMD.

It seems that random tests have become flaky on this configuration,
but the failures seem to be clustered in certain tests. Skip them on
this bot to try to get it reliably green again.

  conformance2/renderbuffers/
    multisampled-renderbuffer-initialization
  conformance2/textures/canvas/
    tex-2d-rgb9_e5-rgb-float
  conformance2/textures/canvas/
    tex-2d-rgb9_e5-rgb-half_float
  conformance2/textures/canvas/
    tex-3d-rg8-rg-unsigned_byte
  conformance2/textures/image_bitmap_from_canvas/
    tex-2d-rgb9_e5-rgb-float
  conformance2/textures/image_bitmap_from_canvas/
    tex-2d-rgb9_e5-rgb-half_float
  deqp/functional/gles3/texturefiltering/
    2d_array_combinations_05.html

Bug: 844483
Change-Id: I903a3641dcc3be6aff4096258cd22f6b45701483
Tbr: jmadill@chromium.org
Tbr: ynovikov@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/1395185Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#619855}

content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

@@ -206,6 +206,30 @@ class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
         ['win', ('nvidia', 0x1cb3), 'opengl'], bug=822733)
 
     # Win / AMD
+
+    # Recently many tests have become flaky on this configuration, returning
+    # (72, 72, 72) when reading back pixels, rather than the expected values.
+    # Going to try to skip the individual failing tests, rather than adding a
+    # wildcard flaky suppression for all of the tests.
+    self.Skip('conformance2/renderbuffers/' +
+              'multisampled-renderbuffer-initialization.html',
+              ['win', 'amd', 'd3d11'], bug=844483)
+    self.Skip('conformance2/textures/canvas/tex-2d-rgb9_e5-rgb-float.html',
+              ['win', 'amd', 'd3d11'], bug=844483)
+    self.Skip('conformance2/textures/canvas/tex-2d-rgb9_e5-rgb-half_float.html',
+              ['win', 'amd', 'd3d11'], bug=844483)
+    self.Skip('conformance2/textures/canvas/tex-3d-rg8-rg-unsigned_byte.html',
+              ['win', 'amd', 'd3d11'], bug=844483)
+    self.Skip('conformance2/textures/image_bitmap_from_canvas/' +
+              'tex-2d-rgb9_e5-rgb-float.html',
+              ['win', 'amd', 'd3d11'], bug=844483)
+    self.Skip('conformance2/textures/image_bitmap_from_canvas/' +
+              'tex-2d-rgb9_e5-rgb-half_float.html',
+              ['win', 'amd', 'd3d11'], bug=844483)
+    self.Skip('deqp/functional/gles3/texturefiltering/' +
+              '2d_array_combinations_05.html',
+              ['win', 'amd', 'd3d11'], bug=844483)
+
     self.Fail('conformance2/rendering/blitframebuffer-stencil-only.html',
         ['win', 'amd', 'd3d11'], bug=483282) # owner:jmadill