Simplify security_interstitials::ControllerClient and other related classes

components/security_interstitials/core/controller_client.cc

Index: components/security_interstitials/core/controller_client.cc
diff --git a/components/security_interstitials/core/controller_client.cc b/components/security_interstitials/core/controller_client.cc
index 1bf60bab51090cec9f529aa44f048f1db8215755..e38fc18dd7958258a364567ee0b554b5505e6c27 100644
--- a/components/security_interstitials/core/controller_client.cc
+++ b/components/security_interstitials/core/controller_client.cc
@@ -22,18 +22,16 @@ const char kPrivacyLinkHtml[] =
     "<a id=\"privacy-link\" href=\"\" onclick=\"sendCommand(%d); "
     "return false;\" onmousedown=\"return false;\">%s</a>";
 
-ControllerClient::ControllerClient() {}
+ControllerClient::ControllerClient(
+    std::unique_ptr<MetricsHelper> metrics_helper)
+    : metrics_helper_(std::move(metrics_helper)) {}
+
 ControllerClient::~ControllerClient() {}
 
 MetricsHelper* ControllerClient::metrics_helper() const {
   return metrics_helper_.get();
 }
 
-void ControllerClient::set_metrics_helper(
-    std::unique_ptr<MetricsHelper> metrics_helper) {
-  metrics_helper_ = std::move(metrics_helper);
-}
-
 void ControllerClient::SetReportingPreference(bool report) {
   GetPrefService()->SetBoolean(GetExtendedReportingPrefName(), report);
   metrics_helper_->RecordUserInteraction(