Adding a short blacklist period after every previews opt out

components/previews/core/previews_experiments.h

Index: components/previews/core/previews_experiments.h
diff --git a/components/previews/core/previews_experiments.h b/components/previews/core/previews_experiments.h
index 9c8d7add0574d9a8f0a42d6a9bcdd75d41866221..7a56d98119dc7809c5cff2d016f0e299871c7087 100644
--- a/components/previews/core/previews_experiments.h
+++ b/components/previews/core/previews_experiments.h
@@ -18,20 +18,23 @@ size_t MaxStoredHistoryLengthForBlackList();
 // The maximum number of hosts allowed in the in memory black list.
 size_t MaxInMemoryHostsInBlackList();
 
 // The number of recent navigations that were opted out of that would trigger
 // the host to be blacklisted.
 int BlackListOptOutThreshold();
 
 // The amount of time a host remains blacklisted due to opt outs.
 base::TimeDelta BlackListDuration();
 
+// The amount of time after any opt out that no previews should be shown.
+base::TimeDelta SingleOptOutDuration();
+
 }  // namespace params
 
 // Returns true if any client-side previews experiment is active.
 bool IsIncludedInClientSidePreviewsExperimentsFieldTrial();
 
 // Returns true if the field trial that should enable offline pages for
 // prohibitvely slow networks is active.
 bool IsOfflinePreviewsEnabled();
 
 // Sets the appropriate state for field trial and variations to imitate the