WebGL: suppress AMD test failure

conformance2/textures/misc/copy-texture-image-same-texture.html is
failing on AMD even after http://crrev.com/c/1356330. Suppressing the
failure.

TBR: kbr@chromium.org
Bug: 809233, 911216
Change-Id: I56138fe20025eb4836f9b588755fcdc71ba88055
Reviewed-on: https://chromium-review.googlesource.com/c/1359129Reviewed-by: James Darpinian <jdarpinian@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: James Darpinian <jdarpinian@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613230}

content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

@@ -1041,6 +1041,8 @@ class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
     self.Fail('conformance2/vertex_arrays/' +
         'vertex-array-object-and-disabled-attributes.html',
         ['linux', 'amd'], bug=899754)
+    self.Fail('conformance2/textures/misc/copy-texture-image-same-texture.html',
+        ['linux', 'no_passthrough', 'amd'], bug=911216)
 
     self.Fail('deqp/functional/gles3/texturespecification/' +
         'teximage2d_pbo_cube_00.html',