Assertion removed in print_preview_pdf_generated.cc.

chrome/browser/ui/webui/print_preview/print_preview_ui.cc

 // 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.
 
 #include "chrome/browser/ui/webui/print_preview/print_preview_ui.h"
 
 #include <map>
 
 #include "base/id_map.h"
 #include "base/lazy_instance.h"
@@ skipping 603 matching lines @@
 }
 
 // static
 void PrintPreviewUI::SetDelegateForTesting(TestingDelegate* delegate) {
   g_testing_delegate = delegate;
 }
 
 void PrintPreviewUI::SetSelectedFileForTesting(const base::FilePath& path) {
   handler_->FileSelected(path, 0, NULL);
 }
+
+void PrintPreviewUI::SetCallbackForTesting(
+    const base::Closure* callback) {
+  handler_->SetCallbackForTesting(callback);
+}