Print preview not showing if default print is invalid.

chrome/browser/ui/webui/print_preview_data_source.cc

 // Copyright (c) 2011 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_data_source.h"
 
 #include <algorithm>
 
 #include "base/message_loop.h"
 #include "base/string_number_conversions.h"
@@ skipping 18 matching lines @@
   AddLocalizedString("title", IDS_PRINT_PREVIEW_TITLE);
   AddLocalizedString("loading", IDS_PRINT_PREVIEW_LOADING);
 #if defined(GOOGLE_CHROME_BUILD)
   AddString("noPlugin", l10n_util::GetStringFUTF16(
       IDS_PRINT_PREVIEW_NO_PLUGIN, ASCIIToUTF16("chrome://plugins/")));
 #else
   AddLocalizedString("noPlugin", IDS_PRINT_PREVIEW_NO_PLUGIN);
 #endif
   AddLocalizedString("launchNativeDialog", IDS_PRINT_PREVIEW_NATIVE_DIALOG);
   AddLocalizedString("previewFailed", IDS_PRINT_PREVIEW_FAILED);
+  AddLocalizedString("invalidDefaultPrinter",
+                     IDS_PRINT_PREVIEW_INVALID_DEFAULT_PRINTER);
   AddLocalizedString("initiatorTabCrashed",
                      IDS_PRINT_PREVIEW_INITIATOR_TAB_CRASHED);
   AddLocalizedString("initiatorTabClosed",
                      IDS_PRINT_PREVIEW_INITIATOR_TAB_CLOSED);
   AddLocalizedString("reopenPage", IDS_PRINT_PREVIEW_REOPEN_PAGE);
 
   AddLocalizedString("printButton", IDS_PRINT_PREVIEW_PRINT_BUTTON);
   AddLocalizedString("cancelButton", IDS_PRINT_PREVIEW_CANCEL_BUTTON);
   AddLocalizedString("printing", IDS_PRINT_PREVIEW_PRINTING);
 
@@ skipping 81 matching lines @@
           url_substr[0], page_index, &data);
   }
   if (data.get()) {
     SendResponse(request_id, data);
     return;
   }
   // Invalid request.
   scoped_refptr<RefCountedBytes> empty_bytes(new RefCountedBytes);
   SendResponse(request_id, empty_bytes);
 }