Remove SafeBrowsing LightSpeed experiment code.

chrome/browser/safe_browsing/safe_browsing_service.cc

Index: chrome/browser/safe_browsing/safe_browsing_service.cc
diff --git a/chrome/browser/safe_browsing/safe_browsing_service.cc b/chrome/browser/safe_browsing/safe_browsing_service.cc
index 5a3813c70848b7bd7d513b71a7ee36237cc457f2..1b762f2a4960ca0260a7299321e86d0812f89017 100644
--- a/chrome/browser/safe_browsing/safe_browsing_service.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_service.cc
@@ -12,6 +12,7 @@
 #include "base/command_line.h"
 #include "base/debug/leak_tracker.h"
 #include "base/lazy_instance.h"
+#include "base/metrics/field_trial.h"
 #include "base/path_service.h"
 #include "base/prefs/pref_change_registrar.h"
 #include "base/prefs/pref_service.h"
@@ -38,7 +39,6 @@
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "components/startup_metric_utils/startup_metric_utils.h"
-#include "components/variations/variations_associated_data.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/cookie_store_factory.h"
 #include "content/public/browser/notification_service.h"
@@ -583,11 +583,6 @@ void SafeBrowsingService::RefreshState() {
     }
   }
 
-  // TODO(asvitkine): Experimental code for measuring start up impact of SB.
-  // Remove when experimentation is complete. http://crbug.com/450037
-  if (!variations::GetVariationParamValue("LightSpeed", "DisableSB").empty())
-    enable = false;
-
   if (enable)
     Start();
   else