GitLab

- Update ProfileAuthData to transfer cookie from sign-in webview;
- Passing back usingSAML flag for auth code authentication and use
  it to set has_auth_cookie flag when SAML is used;
- Update UserCloudPolicyManagerChromeOS to fetch initial policy from
  correct auth request context;
- Enable SAMLPolicyTest for WebView;

BUG=461505

Review URL: https://codereview.chromium.org/1021383002

Cr-Commit-Position: refs/heads/master@{#322223}