Fix WebGL 2.0 expectations and skip a test with an assertion failure.

content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

 # Copyright (c) 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 import os
 
 from webgl_conformance_expectations import WebGLConformanceExpectations
 
 # See the GpuTestExpectations class for documentation.
 
 class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
@@ skipping 129 matching lines @@
         ['win8'], bug=483282)
     self.Fail('conformance2/textures/svg_image/tex-image-and-sub-image-2d' +
         '-with-svg-image-rgb5_a1-rgba-unsigned_byte.html',
         ['win8'], bug=483282)
     self.Fail('conformance2/textures/video/tex-image-and-sub-image-2d' +
         '-with-video-rgb565-rgb-unsigned_byte.html',
         ['win8'], bug=483282)
     self.Fail('conformance2/textures/video/tex-image-and-sub-image-2d' +
         '-with-video-rgb5_a1-rgba-unsigned_byte.html',
         ['win8'], bug=483282)
+    # Windows Debug. Causing assertions in the GPU process which raise
+    # a dialog box, so have to skip them rather than mark them as
+    # failing.
+    self.Skip('conformance2/textures/canvas/tex-image-and-sub-image-2d' +
+        '-with-canvas-rgba8-rgba-unsigned_byte.html',
+        ['win', 'debug'], bug=542901)
 
     # Mac only.
     self.Skip('deqp/data/gles3/shaders/qualification_order.html',
         ['mac'], bug=483282)
     self.Skip('deqp/data/gles3/shaders/scoping.html',
         ['mac'], bug=483282)
     self.Skip('deqp/functional/gles3/defaultvertexattribute.html',
         ['mac'], bug=483282)
     self.Skip('deqp/functional/gles3/floatstatequery.html',
         ['mac'], bug=483282)
@@ skipping 70 matching lines @@
     # Linux NVIDIA only.
     self.Skip('deqp/functional/gles3/shaderswitch.html',
         ['linux', 'nvidia'], bug=483282)
     # Linux AMD only (but fails on all Linux, so not specified as AMD specific)
     # It looks like AMD shader compiler rejects many valid ES3 semantics.
     self.Skip('deqp/data/gles3/shaders/arrays.html', ['linux'], bug=483282)
     self.Skip('deqp/data/gles3/shaders/constant_expressions.html',
         ['linux'], bug=483282)
     self.Skip('deqp/data/gles3/shaders/qualification_order.html',
         ['linux'], bug=483282)