base: Remove an unused member from MessagePumpLibevent::FileDescriptorWatcher

base/message_pump_libevent.h

Index: base/message_pump_libevent.h
diff --git a/base/message_pump_libevent.h b/base/message_pump_libevent.h
index e477036b1127ce1078c7eabc5fffcb50f5848d26..957c5480b465f699d3e36a56e2eb7cdf4ec3e1ce 100644
--- a/base/message_pump_libevent.h
+++ b/base/message_pump_libevent.h
@@ -71,7 +71,7 @@ class BASE_EXPORT MessagePumpLibevent : public MessagePump {
 
     // Called by MessagePumpLibevent, ownership of |e| is transferred to this
     // object.
-    void Init(event* e, bool is_persistent);
+    void Init(event* e);
 
     // Used by MessagePumpLibevent to take ownership of event_.
     event *ReleaseEvent();
@@ -84,7 +84,6 @@ class BASE_EXPORT MessagePumpLibevent : public MessagePump {
     void OnFileCanReadWithoutBlocking(int fd, MessagePumpLibevent* pump);
     void OnFileCanWriteWithoutBlocking(int fd, MessagePumpLibevent* pump);
 
-    bool is_persistent_;  // false if this event is one-shot.
     event* event_;
     MessagePumpLibevent* pump_;
     Watcher* watcher_;