[notifications] Bump histogram milestone

Bump ServiceWorker.NotificationCloseEvent.Time histogram to M90.

Fixed: 1125765
Change-Id: Ic49c555f5c96b040e0d3bb9c3055d90d16feff87
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2533360
Commit-Queue: Nina Satragno <nsatragno@chromium.org>
Commit-Queue: Alexei Svitkine <asvitkine@chromium.org>
Auto-Submit: Nina Satragno <nsatragno@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826557}

tools/metrics/histograms/histograms_xml/service/histograms.xml

@@ -659,7 +659,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ServiceWorker.NotificationCloseEvent.Time" units="ms"
-    expires_after="M87">
+    expires_after="M90">
   <owner>nsatragno@chromium.org</owner>
   <owner>peter@chromium.org</owner>
   <summary>