X11: Use better visuals for OpenGL

gpu/ipc/common/gpu_info.mojom

Index: gpu/ipc/common/gpu_info.mojom
diff --git a/gpu/ipc/common/gpu_info.mojom b/gpu/ipc/common/gpu_info.mojom
index 0b6ce66ed77d7c4b8c5873fb740b10591c0cf94b..2dc028066877cdf4ecd37af97433ddb954630dd1 100644
--- a/gpu/ipc/common/gpu_info.mojom
+++ b/gpu/ipc/common/gpu_info.mojom
@@ -110,4 +110,6 @@ struct GpuInfo {
   array<VideoEncodeAcceleratorSupportedProfile>
     video_encode_accelerator_supported_profiles;
   bool jpeg_decode_accelerator_supported;
+  uint64 system_visual;

[dcheng, 2016/09/27 23:25:51]

+rockot, mojo doesn't have any way to only define certain members on certain
platforms, right?

[Tom (Use chromium acct), 2016/09/28 18:36:01]

I don't think so :S  
dx_diagnostics_info_state is only on OS_WIN, but it doesn't look like there's
anything special going on with it here.

+  uint64 rgba_visual;
 };