Initial commit of sync engine code to browser/sync....

chrome/browser/sync/util/event_sys.h

+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_SYNC_UTIL_EVENT_SYS_H_
+#define CHROME_BROWSER_SYNC_UTIL_EVENT_SYS_H_
+
+#include "chrome/browser/sync/util/pthread_helpers_fwd.h"
+
+// An abstract base class for listening to events.
+//
+// Don't inherit from this class yourself. Using NewEventListenerHookup() is
+// much easier.
+template <typename EventType>
+class EventListener {
+ public:
+  virtual void HandleEvent(const EventType& event) = 0;
+};
+
+// See the -inl.h for details about the following.
+
+template <typename EventTraits, typename NotifyLock = PThreadNoLock,
+          typename ScopedNotifyLocker = PThreadScopedLock<NotifyLock> >
+class EventChannel;
+
+class EventListenerHookup;
+
+template <typename EventChannel, typename CallbackObject,
+          typename CallbackMethod>
+EventListenerHookup* NewEventListenerHookup(EventChannel* channel,
+                                            CallbackObject* cbobject,
+                                            CallbackMethod cbmethod);
+
+template <typename EventChannel, typename CallbackObject,
+          typename CallbackMethod, typename CallbackArg0>
+EventListenerHookup* NewEventListenerHookup(EventChannel* channel,
+                                            CallbackObject* cbobject,
+                                            CallbackMethod cbmethod,
+                                            CallbackArg0 arg0);
+
+#endif  // CHROME_BROWSER_SYNC_UTIL_EVENT_SYS_H_