Extend Net.HttpAuthPromptType expiry to M90

Bug: 400380
Change-Id: I8abd27ae269bd0040f12c038a14223c5989a43f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2460875Reviewed-by: Emily Stark <estark@chromium.org>
Reviewed-by: Chris Thompson <cthomp@chromium.org>
Commit-Queue: Mustafa Emre Acer <meacer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817124}

tools/metrics/histograms/histograms_xml/net/histograms.xml

@@ -1454,8 +1454,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Net.HttpAuthPromptType" enum="HttpAuthPromptType"
-    expires_after="M80">
+    expires_after="M90">
   <owner>meacer@chromium.org</owner>
+  <owner>src/chrome/browser/ui/login/OWNERS</owner>
   <summary>Type of the HTTP auth prompt displayed.</summary>
 </histogram>