[perfbot sheriff] Disable some blink_perf.events stories.

Disable the following stories that have been failing:

blink_perf.events/EventsDispatchingInDeeplyNestedV0ShadowTrees.html
blink_perf.events/EventsDispatchingInDeeplyNestedV1ShadowTrees.html
blink_perf.events/EventsDispatchingInV0ShadowTrees.html
blink_perf.events/EventsDispatchingInV1ShadowTrees.html

BUG=1115356
R=masonfreed@chromium.org
TBR=masonfreed@chromium.org

Change-Id: I63e125cac6479a069eb0f438d96c4dc23392050a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2351619Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797152}

tools/perf/expectations.config

@@ -48,6 +48,10 @@ crbug.com/986423 [ android-nexus-5x android-webview ] blink_perf.events/EventsDi
 crbug.com/986423 [ android-nexus-5x android-webview ] blink_perf.events/EventsDispatchingInDeeplyNestedV1ShadowTrees.html [ Skip ]
 crbug.com/986423 [ android-nexus-5x android-webview ] blink_perf.events/EventsDispatchingInV0ShadowTrees.html [ Skip ]
 crbug.com/986423 [ android-nexus-5x android-webview ] blink_perf.events/EventsDispatchingInV1ShadowTrees.html [ Skip ]
+crbug.com/1115356 [ android-pixel-2 ] blink_perf.events/EventsDispatchingInDeeplyNestedV0ShadowTrees.html [ Skip ]
+crbug.com/1115356 [ android-pixel-2 ] blink_perf.events/EventsDispatchingInDeeplyNestedV1ShadowTrees.html [ Skip ]
+crbug.com/1115356 [ android-pixel-2 ] blink_perf.events/EventsDispatchingInV0ShadowTrees.html [ Skip ]
+crbug.com/1115356 [ android-pixel-2 ] blink_perf.events/EventsDispatchingInV1ShadowTrees.html [ Skip ]
 
 # Benchmark: blink_perf.layout
 crbug.com/551950 [ android-low-end ] blink_perf.layout/* [ Skip ]