Move all core files in //components/sessions into core/ subdir

components/sessions/session_id.h

Index: components/sessions/session_id.h
diff --git a/components/sessions/session_id.h b/components/sessions/session_id.h
deleted file mode 100644
index f23fb7360c68c742ef17a1ee974473515c325705..0000000000000000000000000000000000000000
--- a/components/sessions/session_id.h
+++ /dev/null
@@ -1,27 +0,0 @@
-// Copyright 2014 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_