[sessions] Remove most knowledge of //chrome from core tab restore code

components/sessions/core/tab_restore_service_client.h

 // Copyright 2015 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_CORE_TAB_RESTORE_SERVICE_CLIENT_H_
 #define COMPONENTS_SESSIONS_CORE_TAB_RESTORE_SERVICE_CLIENT_H_
 
 #include "base/callback.h"
+#include "base/files/file_path.h"
 #include "base/memory/scoped_vector.h"
 #include "components/sessions/session_id.h"
 
 namespace base {
 class CancelableTaskTracker;
 }
 
 namespace sessions {
 struct SessionWindow;
 }
 
+class GURL;
+
 namespace sessions {
 
 struct SessionWindow;
 
 // Callback from TabRestoreServiceClient::GetLastSession.
 // The second parameter is the id of the window that was last active.
 typedef base::Callback<void(ScopedVector<SessionWindow>, SessionID::id_type)>
     GetLastSessionCallback;
 
 // A client interface that needs to be supplied to the tab restore service by
 // the embedder.
 class TabRestoreServiceClient {
  public:
   virtual ~TabRestoreServiceClient() {}
 
+  // Returns the path of the directory to save state into.
+  virtual base::FilePath GetPathToSaveTo() = 0;
+
+  // Returns the URL that corresponds to the new tab page.
+  virtual GURL GetNewTabURL() = 0;
+
   // Returns whether there is a previous session to load.
   virtual bool HasLastSession() = 0;
 
   // Fetches the contents of the last session, notifying the callback when
   // done. If the callback is supplied an empty vector of SessionWindows
   // it means the session could not be restored.
   virtual void GetLastSession(const GetLastSessionCallback& callback,
                               base::CancelableTaskTracker* tracker) = 0;
+
+  // Called when a tab is restored. |url| is the URL that the tab is currently
+  // visiting.
+  virtual void OnTabRestored(const GURL& url) {}
 };
 
 }  // namespace sessions
 
 #endif  // COMPONENTS_SESSIONS_CORE_TAB_RESTORE_SERVICE_CLIENT_H_