Bug 1333162 - Only call gdk_set_program_name in the parent process. r=karlt

Differential Revision: https://phabricator.services.mozilla.com/D70640

--HG--
extra : moz-landing-system : lando

widget/gtk/nsAppShell.cpp

@@ -169,19 +169,24 @@ nsresult nsAppShell::Init() {
     } else {
       screenManager.SetHelper(mozilla::MakeUnique<ScreenHelperGTK>());
     }
-  }
 
     if (gtk_check_version(3, 16, 3) == nullptr) {
       // Before 3.16.3, GDK cannot override classname by --class command line
       // option when program uses gdk_set_program_class().
       //
       // See https://bugzilla.gnome.org/show_bug.cgi?id=747634
+      //
+      // Only bother doing this for the parent process, since it's the one
+      // creating top-level windows. (At this point, a child process hasn't
+      // received the list of registered chrome packages, so the
+      // GetBrandShortName call would fail anyway.)
       nsAutoString brandName;
       mozilla::widget::WidgetUtils::GetBrandShortName(brandName);
       if (!brandName.IsEmpty()) {
         gdk_set_program_class(NS_ConvertUTF16toUTF8(brandName).get());
       }
     }
+  }
 
 #ifdef MOZ_WIDGET_GTK
   if (!sReal_gtk_window_check_resize &&