Clean up DownloadAttribution Finch experiments

chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/stringprintf.h"
 #include "base/time/time.h"
@@ skipping 177 matching lines @@
          IsEventExpired(navigation_events_[0]->last_updated,
                         kNavigationFootprintTTLInSecond)) {
     navigation_events_.pop_front();
     removal_count++;
   }
   return removal_count;
 }
 
 // -----------------SafeBrowsingNavigationObserverManager-----------
 // static
-const base::Feature SafeBrowsingNavigationObserverManager::kDownloadAttribution{
-    "DownloadAttribution", base::FEATURE_ENABLED_BY_DEFAULT};
-// static
 bool SafeBrowsingNavigationObserverManager::IsUserGestureExpired(
     const base::Time& timestamp) {
   return IsEventExpired(timestamp, kUserGestureTTLInSecond);
 }
 
 // static
 GURL SafeBrowsingNavigationObserverManager::ClearEmptyRef(const GURL& url) {
   if (url.has_ref() && url.ref().empty()) {
     url::Replacements<char> replacements;
     replacements.ClearRef();
     return url.ReplaceComponents(replacements);
   }
   return url;
 }
 
 // static
 bool SafeBrowsingNavigationObserverManager::IsEnabledAndReady(
     Profile* profile) {
-  return base::FeatureList::IsEnabled(
-      SafeBrowsingNavigationObserverManager::kDownloadAttribution) &&
-      profile->GetPrefs()->GetBoolean(prefs::kSafeBrowsingEnabled) &&
-      g_browser_process->safe_browsing_service() &&
-      g_browser_process->safe_browsing_service()->navigation_observer_manager();
+  return profile->GetPrefs()->GetBoolean(prefs::kSafeBrowsingEnabled) &&
+         g_browser_process->safe_browsing_service() &&
+         g_browser_process->safe_browsing_service()
+             ->navigation_observer_manager();
 }
 
 SafeBrowsingNavigationObserverManager::SafeBrowsingNavigationObserverManager()
     : navigation_event_list_(kNavigationRecordMaxSize) {
 
   // Schedule clean up in 2 minutes.
   ScheduleNextCleanUpAfterInterval(
       base::TimeDelta::FromSecondsD(kNavigationFootprintTTLInSecond));
 }
 
@@ skipping 352 matching lines @@
             out_result));
     // Stop searching if the size of out_referrer_chain already reached its
     // limit.
     if (out_referrer_chain->size() == kReferrerChainMaxLength)
       return;
     last_main_frame_url_traced = last_nav_event_traced->source_main_frame_url;
   }
 }
 
 }  // namespace safe_browsing