aura: Make 'ui' buildable without gtk.

ui/aura/demo/demo_main.cc

Index: ui/aura/demo/demo_main.cc
diff --git a/ui/aura/demo/demo_main.cc b/ui/aura/demo/demo_main.cc
index d99dc2aab2844a5b223c9665c063e493353a8b31..ca60c8b27c3390b116ab73fbe13a69ea0e7bac0c 100644
--- a/ui/aura/demo/demo_main.cc
+++ b/ui/aura/demo/demo_main.cc
@@ -72,7 +72,7 @@ int main(int argc, char** argv) {
   icu_util::Initialize();
   ResourceBundle::InitSharedInstance("en-US");
 
-#if defined(USE_X11)
+#if defined(TOOLKIT_USES_GTK)

[Ben Goodger (Google), 2011/09/21 16:08:39]

I am confused by this... sense seems reversed??

[sadrul, 2011/09/21 16:14:18]

This is ... a bit weird. When TOOLKIT_USES_GTK is set, the MPX can work both
with and without GTK events, but we don't want GTK events, so we disable them.
When TOOLKIT_USES_GTK is not set, the MPX doesn't know anything about GTK events
at all, so we don't need to explicitly disable gtk events here.

   base::MessagePumpX::DisableGtkMessagePump();
 #endif