[fuchsia] Enable some performance tests

The referenced bug is long closed.

Bug: fuchsia:20851
Change-Id: I29b79d15545b5231f09da91a0afc81451608328d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2404623
Commit-Queue: Tamir Duberstein <tamird@google.com>
Reviewed-by: Fabrice de Gans-Riberi <fdegans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805922}

testing/buildbot/filters/fuchsia.base_perftests.filter

@@ -2,8 +2,3 @@
 -MessageLoopPerfTest.PostTaskRate/1_Posting_Thread
 # crbug.com/848499
 -WaitableEventPerfTest.Throughput
-
-# Can cause hangs on SSH connection to test box
-# https://fuchsia.atlassian.net/browse/NET-1010
--TaskObserverPerfTest.TaskPingPong
--JSONPerfTest.StressTest
\ No newline at end of file