Fix history importing by delaying DownloadManager creation.

content/shell/shell_browser_context.h

Index: content/shell/shell_browser_context.h
diff --git a/content/shell/shell_browser_context.h b/content/shell/shell_browser_context.h
index c6471ee2d08f4e390a010bd7eeebee1a27bb70b9..55ee135c9d9e702f6be915bcb544079a7953cdde 100644
--- a/content/shell/shell_browser_context.h
+++ b/content/shell/shell_browser_context.h
@@ -12,6 +12,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "content/browser/browser_context.h"
 
+class DownloadIdFactory;
 class DownloadManager;
 class DownloadStatusUpdater;
 class GeolocationPermissionContext;
@@ -60,6 +61,7 @@ class ShellBrowserContext : public BrowserContext {
   scoped_ptr<SSLHostState> ssl_host_state_;
   scoped_ptr<DownloadStatusUpdater> download_status_updater_;
   scoped_refptr<ShellDownloadManagerDelegate> download_manager_delegate_;
+  scoped_refptr<DownloadIdFactory> download_id_factory_;
   scoped_refptr<DownloadManager> download_manager_;
   scoped_refptr<net::URLRequestContextGetter> url_request_getter_;
   scoped_refptr<HostZoomMap> host_zoom_map_;