Unittest for fix to allow navigation when there is no history DB....

chrome/test/testing_profile.h

 // Copyright (c) 2009 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_TEST_TESTING_PROFILE_H_
 #define CHROME_TEST_TESTING_PROFILE_H_
 
 #include "base/base_paths.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
@@ skipping 14 matching lines @@
 
   // Creates a new profile by adding |count| to the end of the path. Use this
   // when you need to have more than one TestingProfile running at the same
   // time.
   explicit TestingProfile(int count);
 
   virtual ~TestingProfile();
 
   // Creates the history service. If |delete_file| is true, the history file is
   // deleted first, then the HistoryService is created. As TestingProfile
-  // deletes the directory containing the files used by HistoryService, the
-  // boolean only matters if you're recreating the HistoryService.
-  void CreateHistoryService(bool delete_file);
+  // deletes the directory containing the files used by HistoryService, this
+  // only matters if you're recreating the HistoryService.  If |no_db| is true,
+  // the history backend will fail to initialize its database; this is useful
+  // for testing error conditions.
+  void CreateHistoryService(bool delete_file, bool no_db);
 
   // Creates the BookmkarBarModel. If not invoked the bookmark bar model is
   // NULL. If |delete_file| is true, the bookmarks file is deleted first, then
   // the model is created. As TestingProfile deletes the directory containing
   // the files used by HistoryService, the boolean only matters if you're
   // recreating the BookmarkModel.
   //
   // NOTE: this does not block until the bookmarks are loaded. For that use
   // BlockUntilBookmarkModelLoaded.
   void CreateBookmarkModel(bool delete_file);
@@ skipping 198 matching lines @@
 
   virtual ProfileId GetRuntimeId() {
     return original_profile_->GetRuntimeId();
   }
 
  protected:
   Profile* original_profile_;
 };
 
 #endif  // CHROME_TEST_TESTING_PROFILE_H_