Revert "FBTF: Move the TabRestoreService::Observer into its own file."

chrome/browser/sessions/session_backend.h

 // Copyright (c) 2010 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_BACKEND_H_
 #define CHROME_BROWSER_SESSIONS_SESSION_BACKEND_H_
 #pragma once
 
 #include <vector>
 
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
 #include "chrome/browser/sessions/base_session_service.h"
 #include "chrome/browser/sessions/session_command.h"
-
-namespace net {
-class FileStream;
-}
+#include "net/base/file_stream.h"
 
 // SessionBackend -------------------------------------------------------------
 
 // SessionBackend is the backend used by BaseSessionService. It is responsible
 // for maintaining two files:
 // . The current file, which is the file commands passed to AppendCommands
 //   get written to.
 // . The last file. When created the current file is moved to the last
 //   file.
 //
@@ skipping 60 matching lines @@
 
   // Reads the commands from the current file.
   //
   // On success, the read commands are added to commands. It is up to the
   // caller to delete the commands.
   bool ReadCurrentSessionCommandsImpl(std::vector<SessionCommand*>* commands);
 
  private:
   friend class base::RefCountedThreadSafe<SessionBackend>;
 
-  ~SessionBackend();
+  ~SessionBackend() {}
 
   // If current_session_file_ is open, it is truncated so that it is essentially
   // empty (only contains the header). If current_session_file_ isn't open, it
   // is is opened and the header is written to it. After this
   // current_session_file_ contains no commands.
   // NOTE: current_session_file_ may be NULL if the file couldn't be opened or
   // the header couldn't be written.
   void ResetFile();
 
   // Opens the current file and writes the header. On success a handle to
@@ skipping 32 matching lines @@
   // Main thread, all others on the IO thread, hence lazy initialization.
   bool inited_;
 
   // If true, the file is empty (no commands have been added to it).
   bool empty_file_;
 
   DISALLOW_COPY_AND_ASSIGN(SessionBackend);
 };
 
 #endif  // CHROME_BROWSER_SESSIONS_SESSION_BACKEND_H_