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

chrome/browser/sync/engine/client_command_channel.h

+// Copyright (c) 2006-2009 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_ENGINE_CLIENT_COMMAND_CHANNEL_H_
+#define CHROME_BROWSER_SYNC_ENGINE_CLIENT_COMMAND_CHANNEL_H_
+
+#include "chrome/browser/sync/protocol/sync.pb.h"
+#include "chrome/browser/sync/util/event_sys.h"
+
+namespace browser_sync {
+
+// Commands for the client come back in sync responses, which is kind
+// of inconvenient because some services (like the bandwidth throttler)
+// want to know about them.  So to avoid explicit dependencies on this
+// protocol behavior, the syncer dumps all client commands onto a shared
+// client command channel.
+
+struct ClientCommandChannelTraits {
+  typedef const sync_pb::ClientCommand* EventType;
+  static inline bool IsChannelShutdownEvent(const EventType &event) {

[idana, 2009/09/10 05:44:37]

nit: "const EventType &event" -> "const EventType& event"

+    return 0 == event;
+  }
+};
+
+typedef EventChannel<ClientCommandChannelTraits, PThreadMutex>
+    ClientCommandChannel;
+
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_ENGINE_CLIENT_COMMAND_CHANNEL_H_