urlmon: Use file content to verify MIME type reported by file protocol handler

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
http://testbot.winehq.org/JobDetails.pl?Key=18815

Your paranoid android.


=== WXPPROSP3 (32 bit protocol) ===
protocol.c:1046: Test failed: unexpected call ReportResult
protocol.c:1051: Test failed: hrResult = 00000000, expected: 80004004
protocol.c:2838: Test failed: Read failed: 00000001