Add a global build define to determine if the client can draw in the titlebar...

old-configure.in

@@ -2169,6 +2169,7 @@ MOZ_SERVICES_HEALTHREPORT=1
 MOZ_SERVICES_SYNC=1
 MOZ_USERINFO=1
 NSS_DISABLE_DBM=
+MOZ_CAN_DRAW_IN_TITLEBAR=
 
 case "$target_os" in
     mingw*)
@@ -2703,6 +2704,22 @@ x86_64 | arm | aarch64 | x86 | ppc* | ia64)
 
 esac
 
+dnl ========================================================
+dnl = Client drawing in titlebar
+dnl ========================================================
+if test -n "$MOZ_CAN_DRAW_IN_TITLEBAR"; then
+    case "$OS_TARGET" in
+    WINNT|Darwin)
+        AC_DEFINE(MOZ_CAN_DRAW_IN_TITLEBAR)
+        ;;
+    *)
+        AC_MSG_ERROR([Drawing in the titlebar is only supported on Windows and Macintosh targets])
+        ;;
+    esac
+fi
+
+AC_SUBST(MOZ_CAN_DRAW_IN_TITLEBAR)
+
 dnl ========================================================
 dnl = Enable WebRTC code
 dnl ========================================================

toolkit/modules/AppConstants.jsm

@@ -209,7 +209,7 @@ MOZ_SAFE_BROWSING:
 #endif
 
   CAN_DRAW_IN_TITLEBAR:
-#ifdef CAN_DRAW_IN_TITLEBAR
+#ifdef MOZ_CAN_DRAW_IN_TITLEBAR
   true,
 #else
   false,

toolkit/modules/LightweightThemeConsumer.jsm

@@ -147,7 +147,7 @@ LightweightThemeConsumer.prototype = {
         footer.removeAttribute("lwthemefooter");
     }
 
-#ifdef XP_MACOSX
+#if defined(XP_MACOSX) && defined(MOZ_CAN_DRAW_IN_TITLEBAR)
     // On OS X, we extend the lightweight theme into the titlebar, which means setting
     // the chromemargin attribute. Some XUL applications already draw in the titlebar,
     // so we need to save the chromemargin value before we overwrite it with the value

toolkit/modules/moz.build

@@ -92,9 +92,6 @@ EXTRA_PP_JS_MODULES += [
     'WindowDraggingUtils.jsm',
 ]
 
-if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('windows', 'cocoa'):
-    DEFINES['CAN_DRAW_IN_TITLEBAR'] = 1
-
 if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('windows', 'gtk2', 'gtk3'):
     DEFINES['MENUBAR_CAN_AUTOHIDE'] = 1