Simplify security_interstitials::ControllerClient and other related classes

ios/chrome/browser/interstitials/ios_security_interstitial_page.h

 // Copyright 2015 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.
 
 #ifndef IOS_CHROME_BROWSER_INTERSTITIALS_IOS_SECURITY_INTERSTITIAL_PAGE_H_
 #define IOS_CHROME_BROWSER_INTERSTITIALS_IOS_SECURITY_INTERSTITIAL_PAGE_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "ios/web/public/interstitials/web_interstitial_delegate.h"
 #include "url/gurl.h"
 
-class IOSChromeControllerClient;
-
 namespace base {
 class DictionaryValue;
 }
 
-namespace security_interstitials {
-class MetricsHelper;
-}
-
 namespace web {
 class WebInterstitial;
 class WebState;
 }
 
 class IOSSecurityInterstitialPage : public web::HtmlWebInterstitialDelegate {
  public:
   IOSSecurityInterstitialPage(web::WebState* web_state,
                               const GURL& request_url);
   ~IOSSecurityInterstitialPage() override;
@@ skipping 35 matching lines @@
   const GURL request_url_;
 
   // Once non-null, the |web_interstitial_| takes ownership of this
   // IOSSecurityInterstitialPage instance.
   web::WebInterstitial* web_interstitial_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSSecurityInterstitialPage);
 };
 
 #endif  // IOS_CHROME_BROWSER_INTERSTITIALS_IOS_SECURITY_INTERSTITIAL_PAGE_H_