Revert 212948 "Made MessagePump a non-thread safe class."

trunk/src/base/message_loop/message_pump_android.h

Index: trunk/src/base/message_loop/message_pump_android.h
===================================================================
--- trunk/src/base/message_loop/message_pump_android.h	(revision 212951)
+++ trunk/src/base/message_loop/message_pump_android.h	(working copy)
@@ -22,7 +22,6 @@
 class BASE_EXPORT MessagePumpForUI : public MessagePump {
  public:
   MessagePumpForUI();
-  virtual ~MessagePumpForUI();
 
   virtual void Run(Delegate* delegate) OVERRIDE;
   virtual void Quit() OVERRIDE;
@@ -33,6 +32,9 @@
 
   static bool RegisterBindings(JNIEnv* env);
 
+ protected:
+  virtual ~MessagePumpForUI();
+
  private:
   RunLoop* run_loop_;
   base::android::ScopedJavaGlobalRef<jobject> system_message_handler_obj_;