Remove IOObservers from MessageLoopForIO.

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 667cf1e4c74bb1b78ce0a45a4886442672c98ae0..67e2fb6e53178c6a2b4b9ba69a2ebb8621d4e172 100644
--- a/base/message_loop/message_loop.h
+++ b/base/message_loop/message_loop.h
@@ -660,12 +660,10 @@ class BASE_EXPORT MessageLoopForIO : public MessageLoop {
 #if defined(OS_WIN)
   typedef MessagePumpForIO::IOHandler IOHandler;
   typedef MessagePumpForIO::IOContext IOContext;
-  typedef MessagePumpForIO::IOObserver IOObserver;
 #elif defined(OS_IOS)
   typedef MessagePumpIOSForIO::Watcher Watcher;
   typedef MessagePumpIOSForIO::FileDescriptorWatcher
       FileDescriptorWatcher;
-  typedef MessagePumpIOSForIO::IOObserver IOObserver;
 
   enum Mode {
     WATCH_READ = MessagePumpIOSForIO::WATCH_READ,
@@ -676,7 +674,6 @@ class BASE_EXPORT MessageLoopForIO : public MessageLoop {
   typedef MessagePumpLibevent::Watcher Watcher;
   typedef MessagePumpLibevent::FileDescriptorWatcher
       FileDescriptorWatcher;
-  typedef MessagePumpLibevent::IOObserver IOObserver;
 
   enum Mode {
     WATCH_READ = MessagePumpLibevent::WATCH_READ,
@@ -685,9 +682,6 @@ class BASE_EXPORT MessageLoopForIO : public MessageLoop {
   };
 #endif
 
-  void AddIOObserver(IOObserver* io_observer);
-  void RemoveIOObserver(IOObserver* io_observer);
-
 #if defined(OS_WIN)
   // Please see MessagePumpWin for definitions of these methods.
   void RegisterIOHandler(HANDLE file, IOHandler* handler);