Resurrect the cloud printer driver.

cloud_print/virtual_driver/win/virtual_driver_helpers.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 "cloud_print/virtual_driver/win/virtual_driver_helpers.h"
+
+#include <windows.h>
+#include <winspool.h>
+
+#include "base/files/file_util.h"
+#include "base/logging.h"
+#include "base/strings/string16.h"
+#include "base/win/windows_version.h"
+#include "cloud_print/common/win/cloud_print_utils.h"
+
+namespace cloud_print {
+
+void DisplayWindowsMessage(HWND hwnd,
+                           HRESULT hr,
+                           const base::string16& caption) {
+  ::MessageBox(hwnd, GetErrorMessage(hr).c_str(), caption.c_str(), MB_OK);
+}
+
+HRESULT GetPrinterDriverDir(base::FilePath* path) {
+  BYTE driver_dir_buffer[MAX_PATH * sizeof(wchar_t)];
+  DWORD needed = 0;
+  if (!GetPrinterDriverDirectory(NULL, NULL, 1, driver_dir_buffer,
+                                 MAX_PATH * sizeof(wchar_t), &needed)) {
+    // We could try to allocate a larger buffer if needed > MAX_PATH
+    // but that really shouldn't happen.
+    return cloud_print::GetLastHResult();
+  }
+  *path = base::FilePath(reinterpret_cast<wchar_t*>(driver_dir_buffer));
+
+  // The XPS driver is a "Level 3" driver
+  *path = path->Append(L"3");
+  return S_OK;
+}
+}