Tweak ifdefs for MessageLoopForUI::Add/RemoveObserver

This is necessitated by our building of base for tools. In particular
if I set OS_ANDROID and USE_AURA then the host is built with OS_LINUX
and USE_AURA, but none of the other flags we normally set if USE_AURA
is set for OS_LINUX.

And yes, I really need to spend time and refactor messageloop. It is
such a mess of ifdefs right now.

BUG=none
TEST=none
[email protected]

Review URL: https://codereview.chromium.org/129873003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244386 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/base/message_loop/message_loop.h b/base/message_loop/message_loop.h
index 04709e6..59c6cdc4 100644
--- a/base/message_loop/message_loop.h
+++ b/base/message_loop/message_loop.h
@@ -580,12 +580,15 @@
   // never be called. Instead use Start(), which will forward all the native UI
   // events to the Java message loop.
   void Start();
-#elif !defined(OS_MACOSX)
+#endif
 
+#if !defined(OS_NACL) && (defined(TOOLKIT_GTK) || defined(USE_OZONE) || \
+                          defined(OS_WIN) || defined(USE_X11))
   // Please see message_pump_win/message_pump_glib for definitions of these
   // methods.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
+#endif
 
 #if defined(OS_WIN)
   // Plese see MessagePumpForUI for definitions of this method.
@@ -602,11 +605,12 @@
   friend class MessagePumpOzone;
 #endif
 
+#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
   // TODO(rvargas): Make this platform independent.
   MessagePumpForUI* pump_ui() {
     return static_cast<MessagePumpForUI*>(pump_.get());
   }
-#endif  // !defined(OS_MACOSX)
+#endif
 };
 
 // Do not add any member variables to MessageLoopForUI!  This is important b/c