Move session_id.{cc,h} from chrome/browser/sessions to components/sessions

components/sessions/session_id.h

+// Copyright (c) 2012 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 COMPONENTS_SESSIONS_SESSION_ID_H_
+#define COMPONENTS_SESSIONS_SESSION_ID_H_
+
+#include "base/basictypes.h"
+#include "components/sessions/sessions_export.h"
+
+// Uniquely identifies a tab or window for the duration of a session.
+class SESSIONS_EXPORT SessionID {
+ public:
+  typedef int32 id_type;
+
+  SessionID();
+  ~SessionID() {}
+
+  // Returns the underlying id.
+  void set_id(id_type id) { id_ = id; }
+  id_type id() const { return id_; }
+
+ private:
+  id_type id_;
+};
+
+#endif  // COMPONENTS_SESSIONS_SESSION_ID_H_