Provide an iOS message pump for IO implementation.

base/message_pump_libevent_unittest.cc

Index: base/message_pump_libevent_unittest.cc
diff --git a/base/message_pump_libevent_unittest.cc b/base/message_pump_libevent_unittest.cc
index 94245cec8a91eddbc43fddbd3ddbf8a8ea3a8d0b..2d9fc0ceea48f91f84c95aa70a66ea5f30e58df7 100644
--- a/base/message_pump_libevent_unittest.cc
+++ b/base/message_pump_libevent_unittest.cc
@@ -129,8 +129,9 @@ TEST_F(MessagePumpLibeventTest, DeleteWatcher) {
   MessagePumpLibevent::FileDescriptorWatcher* watcher =
       new MessagePumpLibevent::FileDescriptorWatcher;
   DeleteWatcher delegate(watcher);
-  pump->WatchFileDescriptor(pipefds_[1],
-      false, MessagePumpLibevent::WATCH_READ_WRITE, watcher, &delegate);
+  pump->WatchFileDescriptor(pipefds_[1], false,
+      MessagePumpLibevent::WATCH_READ | MessagePumpLibevent::WATCH_WRITE,

[wtc, 2012/11/21 18:48:42]

This is very long. I think we can still define the enumerator
WATCH_READ_WRITE, while declaring the |mode| argument of
WatchFileDescriptor as int.

[blundell, 2012/11/26 16:02:23]

Done.

+      watcher, &delegate);
 
   // Spoof a libevent notification.
   OnLibeventNotification(pump, watcher);
@@ -153,8 +154,9 @@ TEST_F(MessagePumpLibeventTest, StopWatcher) {
   scoped_refptr<MessagePumpLibevent> pump(new MessagePumpLibevent);
   MessagePumpLibevent::FileDescriptorWatcher watcher;
   StopWatcher delegate(&watcher);
-  pump->WatchFileDescriptor(pipefds_[1],
-      false, MessagePumpLibevent::WATCH_READ_WRITE, &watcher, &delegate);
+  pump->WatchFileDescriptor(pipefds_[1], false,
+      MessagePumpLibevent::WATCH_READ | MessagePumpLibevent::WATCH_WRITE,
+      &watcher, &delegate);
 
   // Spoof a libevent notification.
   OnLibeventNotification(pump, &watcher);