Adding a short blacklist period after every previews opt out

components/previews/core/previews_experiments.cc

Index: components/previews/core/previews_experiments.cc
diff --git a/components/previews/core/previews_experiments.cc b/components/previews/core/previews_experiments.cc
index fa1fd2fe1b34e867f6a96c8b45adf8e846c5251e..9e55f510a50f46d0734d0bcfd2870cf30d37c0cb 100644
--- a/components/previews/core/previews_experiments.cc
+++ b/components/previews/core/previews_experiments.cc
@@ -32,25 +32,32 @@ const char kMaxStoredHistoryLength[] = "stored_history_length";
 // The maximum number of hosts allowed in the in memory black list.
 const char kMaxHostsInBlackList[] = "max_hosts_in_blacklist";
 
 // The number of recent navigations that were opted out of that would trigger
 // the host to be blacklisted.
 const char kOptOutThreshold[] = "opt_out_threshold";
 
 // The amount of time a host remains blacklisted due to opt outs.
 const char kBlackListDurationInDays[] = "black_list_duration_in_days";
 
+// The amount of time after any opt out that no previews should be shown.
+const char kSingleOptOutDurationInSeconds[] =
+    "single_opt_out_duration_in_seconds";
+
 // The string that corresponds to enabled for the variation param experiments.
 const char kExperimentEnabled[] = "true";
 
 // In seconds. Hosts are blacklisted for 30 days.
-constexpr int kDefaultBlackListDurationInDays = 30;
+const int kDefaultBlackListDurationInDays = 30;
+
+// In seconds. Previews are not shown for 5 minutes after an opt out.
+constexpr int kDefaultSingleOptOutDurationInSeconds = 60 * 5;
 
 // Returns the parameter value of |param| as a string. If there is no value for
 // |param|, returns an empty string.
 std::string ParamValue(const std::string& param) {
   if (!IsIncludedInClientSidePreviewsExperimentsFieldTrial())
     return std::string();
   std::map<std::string, std::string> experiment_params;
   if (!variations::GetVariationParams(kClientSidePreviewsFieldTrial,
                                       &experiment_params)) {
     return std::string();
@@ -93,20 +100,29 @@ int BlackListOptOutThreshold() {
 
 base::TimeDelta BlackListDuration() {
   std::string param_value = ParamValue(kBlackListDurationInDays);
   int duration;
   if (!base::StringToInt(param_value, &duration)) {
     return base::TimeDelta::FromDays(kDefaultBlackListDurationInDays);
   }
   return base::TimeDelta::FromDays(duration);
 }
 
+base::TimeDelta SingleOptOutDuration() {
+  std::string param_value = ParamValue(kSingleOptOutDurationInSeconds);
+  int duration;
+  if (!base::StringToInt(param_value, &duration)) {
+    return base::TimeDelta::FromSeconds(kDefaultSingleOptOutDurationInSeconds);
+  }
+  return base::TimeDelta::FromSeconds(duration);
+}
+
 }  // namespace params
 
 bool IsIncludedInClientSidePreviewsExperimentsFieldTrial() {
   // By convention, an experiment in the client-side previews study enables use
   // of at least one client-side previews optimization if its name begins with
   // "Enabled."
   return base::StartsWith(
       base::FieldTrialList::FindFullName(kClientSidePreviewsFieldTrial),
       kEnabled, base::CompareCase::SENSITIVE);
 }