gpu: Use workarounds to selectively enable CMAA

gpu/command_buffer/service/feature_info.cc

Index: gpu/command_buffer/service/feature_info.cc
diff --git a/gpu/command_buffer/service/feature_info.cc b/gpu/command_buffer/service/feature_info.cc
index 451dea08285e04e3aa95161324497a80ebbcfc95..9fa1919d87458ed5d29653d15dac84ae12477ab2 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -892,7 +892,8 @@ void FeatureInfo::InitializeFeatures() {
   if (extensions.Contains("GL_INTEL_framebuffer_CMAA")) {
     feature_flags_.chromium_screen_space_antialiasing = true;
     AddExtensionString("GL_CHROMIUM_screen_space_antialiasing");
-  } else if (enable_cmaa_shaders_switch_ &&
+  } else if ((enable_cmaa_shaders_switch_ ||

[Zhenyao Mo, 2016/06/29 16:59:16]

You should just get rid of this enable_cmaa_shaders_switch_ and its related code
now that we have the driver bug workaround installed.

[robert.bradford, 2016/06/29 17:39:46]

Done.

+              !workarounds_.disable_framebuffer_cmaa) &&
              (gl_version_info_->IsAtLeastGLES(3, 1) ||
               (gl_version_info_->IsAtLeastGL(3, 0) &&
                extensions.Contains("GL_ARB_shading_language_420pack") &&