[Linux] Menubar foreground color is styled using context menu foreground color

[sbatten]

Using VS Code 1.29 insiders on Electron 2.0.12
Ubuntu 18.10 with Yaru GTK3 theme

Expected Behavior
The menubar should have light text with a black background.

Actual behavior
The menubar has dark text on a dark background.

To Reproduce

1. Install and Run VS Code 1.29 insiders
2. See dark text on dark background for menubar

Screenshots
If applicable, add screenshots to help explain your problem.

Additional Information
After tweaking the theme css for the Yaru Ubuntu 18.10 theme, it seems the foreground color for the menubar is being pulled from the context menu color, not the menubar foreground color.

The colors are set here:

electron/atom/browser/ui/views/menu_bar.cc

Line 142 in 74644e5

background_color_ = libgtkui::GetBgColor(menubar_selector);

Related VS Code issue: microsoft/vscode#62593

[joaomoreno]

Duplicate of #15194

[sofianguy]

please follow #15194 for updates