Fix Mojave-style tabs not triggering in fullscreen

Author: ychin

src/MacVim/MMFullScreenWindow.m

@@ -165,7 +165,7 @@ - (void)enterFullScreen
     oldTabBarStyle = [[view tabBarControl] styleName];
 
     NSString *style =
-        shouldUseYosemiteTabBarStyle() ? @"Yosemite" : @"Unified";
+        shouldUseYosemiteTabBarStyle() ? (shouldUseMojaveTabBarStyle() ? @"Mojave" : @"Yosemite") : @"Unified";
     [[view tabBarControl] setStyleNamed:style];
 
     // add text view

src/MacVim/MMWindowController.m

@@ -1751,12 +1751,12 @@ - (void)processAfterWindowPresentedQueue
 
 + (NSString *)tabBarStyleForUnified
 {
-    return shouldUseYosemiteTabBarStyle() ? @"Yosemite" : @"Unified";
+    return shouldUseYosemiteTabBarStyle() ? (shouldUseMojaveTabBarStyle() ? @"Mojave" : @"Yosemite") : @"Unified";
 }
 
 + (NSString *)tabBarStyleForMetal
 {
-    return shouldUseYosemiteTabBarStyle() ? @"Yosemite" : @"Metal";
+    return shouldUseYosemiteTabBarStyle() ? (shouldUseMojaveTabBarStyle() ? @"Mojave" : @"Yosemite") : @"Metal";
 }
 
 @end // MMWindowController (Private)