Try to remove Mac shaderoperator/common_functions suppressions.

The tests have been split up to fall well under the timeout threshold.
Re-enabling to see whether they are now reliable.

Tbr: ynovikov@chromium.org
Bug: 820225
Change-Id: I73986640e500d2e69f94acb7c119425131724865
Reviewed-on: https://chromium-review.googlesource.com/c/1298432Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602551}

content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

@@ -694,8 +694,6 @@ class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
     #     ['highsierra', 'amd'], bug=870856)
     self.Fail('conformance2/textures/misc/tex-base-level-bug.html',
         ['highsierra', 'amd'], bug=870856)
-    self.Fail('deqp/functional/gles3/shaderoperator/common_functions_*.html',
-        ['mac', 'amd'], bug=820225)
     self.Fail('deqp/functional/gles3/transformfeedback/' +
         'array_interleaved_lines.html',
         ['sierra', 'amd'], bug=483282)
@@ -797,8 +795,6 @@ class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
         ['mac', 'no_passthrough', 'intel'], bug=679692)
     self.Fail('deqp/functional/gles3/fbomultisample*',
         ['mac', 'intel'], bug=641209)
-    self.Fail('deqp/functional/gles3/shaderoperator/common_functions_*.html',
-        ['mac', 'intel'], bug=820225)
     self.Fail('deqp/functional/gles3/texturefiltering/2d_combinations_01.html',
         ['mac', 'intel'], bug=606074)
     self.Fail('deqp/functional/gles3/texturefiltering/' +