Extend expiry of WebFont.DownloadTime.LoadError histogram

Now it has the same expiration date as the other WebFont.DownloadTime.*
histograms.

Bug: 1156194
Change-Id: Ie2e9ec544359dc9498a96064964a173b901f7d9c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2622688Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Commit-Queue: Kunihiko Sakamoto <ksakamoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843291}

tools/metrics/histograms/histograms_xml/others/histograms.xml

@@ -18068,7 +18068,7 @@ regressions. -->
 </histogram>
 
 <histogram name="WebFont.DownloadTime.LoadError" units="ms"
-    expires_after="2021-01-20">
+    expires_after="2021-06-13">
   <owner>kenjibaheux@chromium.org</owner>
   <owner>ksakamoto@chromium.org</owner>
   <summary>