Move SecurityInterstitialPage into component

ios/chrome/browser/interstitials/ios_chrome_controller_client.mm

Index: ios/chrome/browser/interstitials/ios_chrome_controller_client.mm
diff --git a/ios/chrome/browser/interstitials/ios_chrome_controller_client.mm b/ios/chrome/browser/interstitials/ios_chrome_controller_client.mm
index 1f5b8b2452a8ee1a973bdf68d69f896ac4f28311..8ba9902727ee995546655887355580d52c280204 100644
--- a/ios/chrome/browser/interstitials/ios_chrome_controller_client.mm
+++ b/ios/chrome/browser/interstitials/ios_chrome_controller_client.mm
@@ -63,16 +63,17 @@ void IOSChromeControllerClient::OpenUrlInCurrentTab(const GURL& url) {
       ui::PAGE_TRANSITION_LINK, false));
 }
 
-const std::string& IOSChromeControllerClient::GetApplicationLocale() {
+const std::string& IOSChromeControllerClient::GetApplicationLocale() const {
   return GetApplicationContext()->GetApplicationLocale();
 }
 
-PrefService* IOSChromeControllerClient::GetPrefService() {
+PrefService* IOSChromeControllerClient::GetPrefService() const {
   return ios::ChromeBrowserState::FromBrowserState(
              web_state_->GetBrowserState())
       ->GetPrefs();
 }
 
-const std::string IOSChromeControllerClient::GetExtendedReportingPrefName() {
+const std::string IOSChromeControllerClient::GetExtendedReportingPrefName()
+    const {
   return std::string();
 }