Make tcp_client_socket_unittest pass on Linux....

base/message_loop.h

Index: base/message_loop.h
===================================================================
--- base/message_loop.h	(revision 2108)
+++ base/message_loop.h	(working copy)
@@ -21,6 +21,8 @@
 // We need this to declare base::MessagePumpWin::Dispatcher, which we should
 // really just eliminate.
 #include "base/message_pump_win.h"
+#elif defined(OS_LINUX)
+#include "base/message_pump_libevent.h"
 #endif
 
 // A MessageLoop is used to process events for a particular thread.  There is
@@ -274,6 +276,12 @@
   base::MessagePumpWin* pump_win() {
     return static_cast<base::MessagePumpWin*>(pump_.get());
   }
+#elif defined(OS_LINUX)
+ public:
+  base::MessagePumpLibevent* pump_libevent() {
+    return static_cast<base::MessagePumpLibevent*>(pump_.get());
+  }
+ protected:
 #endif
 
   // A function to encapsulate all the exception handling capability in the
@@ -359,6 +367,10 @@
 
   scoped_refptr<base::MessagePump> pump_;
 
+#if defined(OS_LINUX)
+  //struct event_base *iopump_;
+#endif
+
   ObserverList<DestructionObserver> destruction_observers_;
 
   // A recursion block that prevents accidentally running additonal tasks when