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

chrome/browser/sessions/session_tab_helper.h

 // Copyright (c) 2011 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_SESSIONS_SESSION_TAB_HELPER_H_
 #define CHROME_BROWSER_SESSIONS_SESSION_TAB_HELPER_H_
 
 #include "base/basictypes.h"
-#include "components/sessions/session_id.h"
+#include "components/sessions/core/session_id.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
 // This class keeps the extension API's windowID up-to-date with the current
 // window of the tab.
 class SessionTabHelper : public content::WebContentsObserver,
                          public content::WebContentsUserData<SessionTabHelper> {
  public:
   ~SessionTabHelper() override;
 
@@ skipping 34 matching lines @@
   // sessions.
   const SessionID session_id_;
 
   // Unique identifier of the window the tab is in.
   SessionID window_id_;
 
   DISALLOW_COPY_AND_ASSIGN(SessionTabHelper);
 };
 
 #endif  // CHROME_BROWSER_SESSIONS_SESSION_TAB_HELPER_H_