gtk: Some code cleanup for the message-pump.

base/message_loop/message_loop.h

Index: base/message_loop/message_loop.h
diff --git a/base/message_loop/message_loop.h b/base/message_loop/message_loop.h
index f22c9044d1b9d30c4d9ff0b601eacd8aa4b765b2..8280ce625b39713b18efcfefe2e552f5c1ede04d 100644
--- a/base/message_loop/message_loop.h
+++ b/base/message_loop/message_loop.h
@@ -90,7 +90,10 @@ class WaitableEvent;
 class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
  public:
 
-#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
+#if defined(TOOLKIT_GTK)
+  typedef void* Dispatcher;

[ccameron, 2013/09/03 23:35:49]

This is the only area where we'd have difficulty -- could we "typedef
MessagePumpGdkObserver GdkObserver" instead?

+  typedef MessagePumpGdkObserver Observer;
+#elif !defined(OS_MACOSX) && !defined(OS_ANDROID)
   typedef MessagePumpDispatcher Dispatcher;
   typedef MessagePumpObserver Observer;
 #endif