Fixed null pointer exception.

printing/backend/win_helper.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 "printing/backend/win_helper.h"
 
 #include <algorithm>
 
 #include "base/file_path.h"
 #include "base/file_version_info.h"
@@ skipping 341 matching lines @@
     return driver_info;
 
   std::string info[4];
   if (driver->pName)
     info[0] = WideToUTF8(driver->pName);
 
   if (driver->pDriverPath) {
     scoped_ptr<FileVersionInfo> version_info(
         FileVersionInfo::CreateFileVersionInfo(
             FilePath(driver->pDriverPath)));
-    info[1] = WideToUTF8(version_info->file_version());
-    info[2] = WideToUTF8(version_info->product_name());
-    info[3] = WideToUTF8(version_info->product_version());
+    if (version_info.get()) {
+      info[1] = WideToUTF8(version_info->file_version());
+      info[2] = WideToUTF8(version_info->product_name());
+      info[3] = WideToUTF8(version_info->product_version());
+    }
   }
 
   for (size_t i = 0; i < arraysize(info); ++i) {
     std::replace(info[i].begin(), info[i].end(), ';', ',');
     driver_info.append(info[i]);
     if (i < arraysize(info) - 1)
       driver_info.append(";");
   }
   return driver_info;
 }
 
 }  // namespace printing