Bug 1570097: Part 1 - Skip some additional tests that timeout on debug. r=mccr8

For some reason, these timeouts aren't reported as timeouts on automation. The
tests just fail after sitting for 5 minutes doing nothing. Locally, though,
they are reported as timeouts.

Either way, they make the test group run 15 minutes longer than necessary.

Differential Revision: https://phabricator.services.mozilla.com/D39930

--HG--
extra : moz-landing-system : lando

docshell/test/navigation/mochitest.ini

@@ -58,6 +58,7 @@ support-files =
 
 [test_bug13871.html]
 fail-if = fission
+skip-if = fission && debug # Times out.
 [test_bug270414.html]
 fail-if = fission
 [test_bug278916.html]
@@ -77,7 +78,9 @@ fail-if = fission
 skip-if = fission && (debug || asan) # Causes shutdown leaks under Fission.
 [test_not-opener.html]
 fail-if = fission
+skip-if = fission && debug # Times out
 [test_opener.html]
+skip-if = fission && debug # Times out
 [test_popup-navigates-children.html]
 fail-if = fission
 [test_reserved.html]