SetIconAPITest.Overview is flaky for network_service_browser_tests

TBR=jam@chromium.org

Bug: 798969, 798791
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_mojo
Change-Id: I03fb83897ffea40444af1f74e1b9f6786c035a70
Reviewed-on: https://chromium-review.googlesource.com/850116
Commit-Queue: Dominic Battré <battre@chromium.org>
Reviewed-by: Dominic Battré <battre@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526959}

testing/buildbot/filters/mojo.fyi.network_browser_tests.filter

@@ -882,8 +882,9 @@
 # Flakes https://logs.chromium.org/v/?s=chromium%2Fbb%2Fchromium.linux%2FLinux_Tests%2F65816%2F%2B%2Frecipes%2Fsteps%2Fnetwork_service_browser_tests%2F0%2Flogs%2FDeclarativeContentApiTest.IsBookmarkedRulesEvaluatedOnBookmarkEvents%2F0
 -DeclarativeContentApiTest.IsBookmarkedRulesEvaluatedOnBookmarkEvents
 
-# Flakes, crbug.com/798969
+# Flakes due to ExtensionBrowserTest::NavigateInRenderer(), crbug.com/798969
 -DeclarativeContentApiTest.DisabledForSpanningIncognito
 -DeclarativeContentApiTest.DisabledForSplitIncognito
 -DeclarativeContentApiTest.EnabledForSpanningIncognito
 -DeclarativeContentApiTest.EnabledForSpanningIncognito
+-SetIconAPITest.Overview