Implement delegation to Metro file pickers.

R=cpu@chromium.org,robertshield@chromium.org
BUG=None
TEST=None


Review URL: https://chromiumcodereview.appspot.com/10310103

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@136624 0039d316-1c4b-4281-b951-d872f2087c98
static bool GetRegistryDescriptionFromExtension(const std::wstring& file_ext,
                                                std::wstring* reg_description) {
  DCHECK(reg_description);
  base::win::RegKey reg_ext(HKEY_CLASSES_ROOT, file_ext.c_str(), KEY_READ);
  std::wstring reg_app;
  if (reg_ext.ReadValue(NULL, &reg_app) == ERROR_SUCCESS && !reg_app.empty()) {
    base::win::RegKey reg_link(HKEY_CLASSES_ROOT, reg_app.c_str(), KEY_READ);
    if (reg_link.ReadValue(NULL, reg_description) == ERROR_SUCCESS)
      return true;
  }
  return false;
}

static bool GetRegistryDescriptionFromExtension(const std::wstring& file_ext,
                                                std::wstring* reg_description) {
  DCHECK(reg_description);
  base::win::RegKey reg_ext(HKEY_CLASSES_ROOT, file_ext.c_str(), KEY_READ);
  std::wstring reg_app;
  if (reg_ext.ReadValue(NULL, &reg_app) == ERROR_SUCCESS && !reg_app.empty()) {
    base::win::RegKey reg_link(HKEY_CLASSES_ROOT, reg_app.c_str(), KEY_READ);
    if (reg_link.ReadValue(NULL, reg_description) == ERROR_SUCCESS)
      return true;
  }
  return false;
}
