Web Inspector: [Network] Cover the type of preflight xhr.
https://bugs.webkit.org/show_bug.cgi?id=113471.

Patch by Pan Deng <pan.deng@intel.com> on 2013-04-16
Reviewed by Vsevolod Vlasov.

Add the Network resource type test to make sure the xhr-preflight is "xhr".

* http/tests/inspector/network-preflight-options-expected.txt:
* http/tests/inspector/network-preflight-options.html:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148500 268f45cc-cd09-0410-ab3c-d52691b4dbfc