Patch from Bug 1621274 has landed.

[ISHIKAWA,chiaki]

https://bugzilla.mozilla.org/show_bug.cgi?id=1621274

This eliminates the major headache in looking at other people's
mochitest log for debug build on try-comm-central.

That is, there are so many hits of an assertion that is related to
incorrect calculation for XUL box  usage.
The stacktraces from the assertion  bloats the log size pretty much, and
because the stacktraces contain so many function names that they often
get in the way of search something else. If the search string matches
function names in the stacktraces, it is really a bother.

I have no idea why others are not disturbed these stackdumps in the log.
Makes me wonder if I am the only person in the world who checks the
content of the log from time to time to make sure my locally created
patches are sane enough.

Just checking the unreliable PASS/FAIL outcome of the test is
insufficient for the following reasons.

Mozilla try-comm-central test framework DOES NOT report or abort tests
that have serious javascript errors, etc.
I can't trust a test framework which reports test success even when the
executed tests throw uncaught errors, for example.

We really need to check the log output more carefully especially after
new features are introduced.
We need a log police or something like that IMHO.

Chiaki