Bug 1319725 - disable the test_reactivate.html; r=jwwang

The test case itself does not really do what it claims.
Disable it now (for landing bug 1244768) and will rework it later.

MozReview-Commit-ID: H2sCX58eypr

--HG--
extra : rebase_source : 0a5165df23cd79e4a3605fa2c2dbfb27055468cf

dom/media/test/mochitest.ini

@@ -812,6 +812,7 @@ skip-if = appname == "seamonkey"
 [test_preserve_playbackrate_after_ui_play.html]
 [test_progress.html]
 [test_reactivate.html]
+skip-if = true # see bug 1319725
 [test_readyState.html]
 [test_referer.html]
 [test_replay_metadata.html]