Bug 1027034 - Properly set up Gtk+3 compatibility headers. r=karlt

--HG--
rename : widget/gtk/compat/gtk/gtkenums.h => widget/gtk/compat-gtk3/gtk/gtkenums.h

config/config.mk

@@ -888,6 +888,9 @@ export NONASCII
 ifdef MOZ_GTK2_CFLAGS
 MOZ_GTK2_CFLAGS := -I$(topsrcdir)/widget/gtk/compat $(MOZ_GTK2_CFLAGS)
 endif
+ifdef MOZ_GTK3_CFLAGS
+MOZ_GTK3_CFLAGS := -I$(topsrcdir)/widget/gtk/compat-gtk3 $(MOZ_GTK3_CFLAGS)
+endif
 
 DEFINES += -DNO_NSPR_10_SUPPORT