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

chrome/browser/history/history_backend.cc

 // 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.
 
 #include "chrome/browser/history/history_backend.h"
 
 #include <set>
 
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
@@ skipping 194 matching lines @@
     text_database_.reset();
   }
 
   if (backend_destroy_task_) {
     // Notify an interested party (typically a unit test) that we're done.
     DCHECK(backend_destroy_message_loop_);
     backend_destroy_message_loop_->PostTask(FROM_HERE, backend_destroy_task_);
   }
 }
 
-void HistoryBackend::Init() {
-  InitImpl();
+void HistoryBackend::Init(bool force_fail) {
+  if (!force_fail)
+    InitImpl();
   delegate_->DBLoaded();
 }
 
 void HistoryBackend::SetOnBackendDestroyTask(MessageLoop* message_loop,
                                              Task* task) {
   if (backend_destroy_task_) {
     DLOG(WARNING) << "Setting more than one destroy task, overriding";
     delete backend_destroy_task_;
   }
   backend_destroy_message_loop_ = message_loop;
@@ skipping 1752 matching lines @@
   return true;
 }
 
 BookmarkService* HistoryBackend::GetBookmarkService() {
   if (bookmark_service_)
     bookmark_service_->BlockTillLoaded();
   return bookmark_service_;
 }
 
 }  // namespace history