Bug 543086. Don't try to build the default plug-in on mac if we don't have pbbuild. It'll just fail. r=ted

modules/plugin/Makefile.in

@@ -68,9 +68,11 @@ ifeq ($(OS_ARCH),OS2)
 TOOL_DIRS += default/os2
 endif
 
+ifdef PBBUILD
 ifeq ($(MOZ_WIDGET_TOOLKIT),cocoa)
 TOOL_DIRS += default/mac
 endif
+endif
 
 ifdef ENABLE_TESTS
 ifneq (,$(filter WINNT Darwin Linux OS2 SunOS,$(OS_ARCH)))