Allow SessionBackend::Init() to occur just-in-time in production builds.

chrome/browser/sessions/base_session_service.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 CHROME_BROWSER_SESSIONS_BASE_SESSION_SERVICE_H_
 #define CHROME_BROWSER_SESSIONS_BASE_SESSION_SERVICE_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/callback.h"
@@ skipping 131 matching lines @@
 
   // Returns true if the entry at specified |url| should be written to disk.
   bool ShouldTrackEntry(const GURL& url);
 
   // Invokes ReadLastSessionCommands with request on the backend thread.
   // If testing, ReadLastSessionCommands is invoked directly.
   Handle ScheduleGetLastSessionCommands(
       InternalGetCommandsRequest* request,
       CancelableRequestConsumerBase* consumer);
 
+  // Returns true if we appear to be running in production, false if
+  // we appear to be running as part of a unit test or if the FILE
+  // thread has gone away.
+  bool RunningInProduction() const;
+
   // In production, this posts the task to the FILE thread.  For
   // tests, it immediately runs the specified task on the current
   // thread.
   bool RunTaskOnBackendThread(const tracked_objects::Location& from_here,
                               const base::Closure& task);
 
   // Max number of navigation entries in each direction we'll persist.
   static const int max_persist_navigation_count;
 
  private:
@@ skipping 22 matching lines @@
   // The number of commands sent to the backend before doing a reset.
   int commands_since_reset_;
 
   // Whether to save the HTTP bodies of the POST requests.
   bool save_post_data_;
 
   DISALLOW_COPY_AND_ASSIGN(BaseSessionService);
 };
 
 #endif  // CHROME_BROWSER_SESSIONS_BASE_SESSION_SERVICE_H_