Merge 95322 - http/tests/history/back-with-fragment-change.php fails on non-Chromium bots

Merge 95322 - http/tests/history/back-with-fragment-change.php fails on non-Chromium bots
https://bugs.webkit.org/show_bug.cgi?id=68242

Skip test on ports on which it fails. Move comment to be inside
<?php> block so that HTTP headers can be set on all platforms (there
must not be any whitespace before the <?php> block).

* http/tests/history/back-with-fragment-change.php:
* platform/gtk/Skipped:
* platform/mac/Skipped:
* platform/qt/Skipped:

TBR=mihaip@chromium.org
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=95835