Revert of Prerender: Hardcode the Silence experiment date

chrome/browser/prerender/prerender_manager.cc

Index: chrome/browser/prerender/prerender_manager.cc
diff --git a/chrome/browser/prerender/prerender_manager.cc b/chrome/browser/prerender/prerender_manager.cc
index 5655372fc5aa88531d6fa8efb5bc029eaf4fa0da..48300bbae5e5b419ef3ea964014765b13faef654 100644
--- a/chrome/browser/prerender/prerender_manager.cc
+++ b/chrome/browser/prerender/prerender_manager.cc
@@ -1261,10 +1261,8 @@
 }
 
 bool PrerenderManager::IsPrerenderSilenceExperiment(Origin origin) const {
-  if (origin == ORIGIN_OFFLINE ||
-      origin == ORIGIN_EXTERNAL_REQUEST_FORCED_CELLULAR) {
+  if (origin == ORIGIN_OFFLINE)
     return false;
-  }
 
   // The group name should contain expiration time formatted as:
   //   "ExperimentYes_expires_YYYY-MM-DDTHH:MM:SSZ".
@@ -1273,16 +1271,6 @@
   const char kExperimentPrefix[] = "ExperimentYes";
   if (!base::StartsWith(group_name, kExperimentPrefix,
                         base::CompareCase::INSENSITIVE_ASCII)) {
-    // The experiment group was not set, use 2016-12-14 PST as the day of the
-    // experiment.
-    base::Time experiment_start;
-    if (!base::Time::FromString("2016-12-14-08:00:00Z", &experiment_start))
-      NOTREACHED();
-    base::Time current_time = GetCurrentTime();
-    if ((experiment_start <= current_time) &&
-        (current_time < experiment_start + base::TimeDelta::FromDays(1))) {
-      return true;
-    }
     return false;
   }
   const char kExperimentPrefixWithExpiration[] = "ExperimentYes_expires_";