During upgrade to the Chromium 61 we have switched from GTK2 to GTK3
and now we have a few warnings about stuff being deprecated in GTK3.
Check any Linux build to get a list of them.

/cc @zcbenz 
atom/browser/ui/views/menu_bar.cc
#include "atom/browser/ui/views/menu_bar.h"
#if defined(USE_X11)
#include "gtk/gtk.h"
#endif
#include "atom/browser/ui/views/menu_delegate.h"
#include "atom/browser/ui/views/submenu_button.h"
#include "ui/base/models/menu_model.h"
#include "ui/views/background.h"
#include "ui/views/layout/box_layout.h"
#if defined(OS_WIN)
#include "ui/gfx/color_utils.h"
#elif defined(USE_X11)
#include "chrome/browser/ui/libgtkui/skia_utils_gtk.h"
#endif
namespace atom {
namespace {
const char kViewClassName[] = "ElectronMenuBar";
const SkColor kDefaultColor = SkColorSetARGB(255, 233, 233, 233);
#if defined(USE_X11)
void GetMenuBarColor(SkColor* enabled, SkColor* disabled, SkColor* highlight,