Unsuppress cube-map-uploads-out-of-order in WebGL 2.0 suite.

This suppression is obsolete. I can't find the commit in which the
suppression was removed from the 1.0 suite.

BUG=473739,682036
TBR=zmo@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2848133002
Cr-Commit-Position: refs/heads/master@{#468200}

content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

@@ -256,8 +256,6 @@ class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
         ['mac'], bug=1832) # khronos WebGL issue
 
     # Mac Retina NVIDIA
-    self.Fail('conformance/textures/misc/cube-map-uploads-out-of-order.html',
-        ['mac', ('nvidia', 0xfe9)], bug=473739)
     self.Fail('deqp/functional/gles3/fbomultisample*',
         ['mac', ('nvidia', 0xfe9)], bug=641209)
     self.Fail('deqp/functional/gles3/framebufferblit/' +