Fix implicit access to raw pointer of scoped_refptr.

ios/web/web_state/ui/crw_web_controller.mm

 // Copyright 2012 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.
 
 #import "ios/web/web_state/ui/crw_web_controller.h"
 
 #import <WebKit/WebKit.h>
 
 #import <objc/runtime.h>
 #include <stddef.h>
@@ skipping 5071 matching lines @@
   }
   [self webPageChanged];
 
   [self updateSSLStatusForCurrentNavigationItem];
 
   // Report cases where SSL cert is missing for a secure connection.
   if (_documentURL.SchemeIsCryptographic()) {
     scoped_refptr<net::X509Certificate> cert =
         web::CreateCertFromChain([_webView certificateChain]);
     UMA_HISTOGRAM_BOOLEAN("WebController.WKWebViewHasCertForSecureConnection",
-                          cert);
+                          static_cast<bool>(cert));
   }
 }
 
 - (void)webView:(WKWebView*)webView
     didFinishNavigation:(WKNavigation*)navigation {
   DCHECK(!_isHalted);
   // Trigger JavaScript driven post-document-load-completion tasks.
   // TODO(crbug.com/546350): Investigate using
   // WKUserScriptInjectionTimeAtDocumentEnd to inject this material at the
   // appropriate time rather than invoking here.
@@ skipping 444 matching lines @@
   }
 
   return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
 }
 
 - (NSString*)refererFromNavigationAction:(WKNavigationAction*)action {
   return [action.request valueForHTTPHeaderField:@"Referer"];
 }
 
 @end