[test] Skip tests that timeout on chromebooks

TBR=gab@chromium.org
NOTRY=true

Bug: chromium:805932
Change-Id: I76e5acb5f2e749f7240abb0cb0596fdf8b72badf
Reviewed-on: https://chromium-review.googlesource.com/895602
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50988}

test/unittests/unittests.status

@@ -3,4 +3,9 @@
 # found in the LICENSE file.
 
 [
+['arch == arm and not simulator_run', {
+  # Timeouts on chromebooks.
+  'ItemParallelJobTest.DistributeItemsMultipleTasks': [SKIP],
+  'ItemParallelJobTest.MoreTasksThanItems': [SKIP],
+}],  # 'arch == arm and not simulator_run'
 ]