More z-index fixes for buildbots.html
More z-index fixes for buildbots.html

Addressing http://code.google.com/p/skia/issues/detail?id=1074
Review URL: https://codereview.appspot.com/7129050

git-svn-id: 32fc27f4dcfb6c0385cd9719852b95fe6680452d@7259 2bbb7eff-a529-9590-31e7-b0007b416f81

Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot