Extend the expiring time for BFcache metrics

Bug: 1117081
Change-Id: I655468fd6748b6e948edc0add545d6fbb7b3272a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2489111Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Alexander Timin <altimin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819525}

tools/metrics/histograms/histograms_xml/back_forward_cache/histograms.xml

@@ -23,7 +23,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="BackForwardCache.AllSites.EvictedAfterDocumentRestoredReason"
     enum="BackForwardCacheEvictedAfterDocumentRestoredReason"
-    expires_after="2020-10-01">
+    expires_after="2021-10-01">
   <owner>hajimehoshi@chromium.org</owner>
   <owner>bfcache-dev@chromium.org</owner>
   <summary>
@@ -85,7 +85,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 <histogram
     name="BackForwardCache.AllSites.HistoryNavigationOutcome.DisabledForRenderFrameHostReason"
     enum="BackForwardCacheDisabledForRenderFrameHostReason"
-    expires_after="2020-10-01">
+    expires_after="2021-10-01">
   <owner>carlscab@chromium.org</owner>
   <owner>hajimehoshi@chromium.org</owner>
   <owner>bfcache-dev@chromium.org</owner>
@@ -139,7 +139,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="BackForwardCache.Eviction.TimeUntilProcessKilled" units="ms"
-    expires_after="2020-10-01">
+    expires_after="2021-10-01">
   <owner>hajimehoshi@chromium.org</owner>
   <owner>bfcache-dev@chromium.org</owner>
   <summary>
@@ -183,7 +183,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="BackForwardCache.HistoryNavigationOutcome"
-    enum="BackForwardCacheHistoryNavigationOutcome" expires_after="2020-10-01">
+    enum="BackForwardCacheHistoryNavigationOutcome" expires_after="2021-10-01">
   <owner>hajimehoshi@chromium.org</owner>
   <owner>bfcache-dev@chromium.org</owner>
   <summary>
@@ -329,7 +329,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="BackForwardCache.ReloadsAfterHistoryNavigation"
     enum="BackForwardCacheReloadsAfterHistoryNavigation"
-    expires_after="2020-10-01">
+    expires_after="2021-10-01">
   <owner>sreejakshetty@chromium.org</owner>
   <owner>altimin@chromium.org</owner>
   <owner>bfcache-dev@chromium.org</owner>
@@ -345,7 +345,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="BackForwardCache.ReloadsAndHistoryNavigations"
     enum="BackForwardCacheReloadsAndHistoryNavigations"
-    expires_after="2020-10-01">
+    expires_after="2021-10-01">
   <owner>sreejakshetty@chromium.org</owner>
   <owner>altimin@chromium.org</owner>
   <owner>bfcache-dev@chromium.org</owner>
@@ -359,7 +359,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="BackForwardCache.Restore.NavigationToFirstPaint" units="ms"
-    expires_after="2020-12-06">
+    expires_after="2021-10-01">
   <owner>sreejakshetty@chromium.org</owner>
   <owner>altimin@chromium.org</owner>
   <owner>bfcache-dev@chromium.org</owner>