[ios] Use -[WKWebView serverTrust] instead of certificateChain on iOS 10.

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 4466 matching lines @@
   }
 
   if (!_SSLStatusUpdater) {
     _SSLStatusUpdater.reset([[CRWSSLStatusUpdater alloc]
         initWithDataSource:self
          navigationManager:navManager
                certGroupID:self.certGroupID]);
     [_SSLStatusUpdater setDelegate:self];
   }
   NSString* host = base::SysUTF8ToNSString(_documentURL.host());
-  NSArray* certChain = [_webView certificateChain];
   BOOL hasOnlySecureContent = [_webView hasOnlySecureContent];
+  base::ScopedCFTypeRef<SecTrustRef> trust;
+// TODO(crbug.com/628696): Remove these guards after moving to iOS10 SDK.
+#if defined(__IPHONE_10_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_10_0
+  if (base::ios::IsRunningOnIOS10OrLater()) {
+    trust.reset([_webView serverTrust], base::scoped_policy::RETAIN);
+  } else {
+    trust = web::CreateServerTrustFromChain([_webView certificateChain], host);
+  }
+#else
+  trust = web::CreateServerTrustFromChain([_webView certificateChain], host);
+#endif
+
   [_SSLStatusUpdater updateSSLStatusForNavigationItem:currentNavItem
                                          withCertHost:host
-                                            certChain:certChain
+                                                trust:std::move(trust)
                                  hasOnlySecureContent:hasOnlySecureContent];
 }
 
 - (void)didUpdateSSLStatusForCurrentNavigationItem {
   if ([_delegate respondsToSelector:
           @selector(
               webControllerDidUpdateSSLStatusForCurrentNavigationItem:)]) {
     [_delegate webControllerDidUpdateSSLStatusForCurrentNavigationItem:self];
   }
 }
@@ skipping 753 matching lines @@
 
 - (void)webViewWebContentProcessDidTerminate:(WKWebView*)webView {
   _certVerificationErrors->Clear();
   [self webViewWebProcessDidCrash];
 }
 
 #pragma mark -
 #pragma mark CRWSSLStatusUpdater DataSource/Delegate Methods
 
 - (void)SSLStatusUpdater:(CRWSSLStatusUpdater*)SSLStatusUpdater
-    querySSLStatusForCertChain:(NSArray*)certChain
-                          host:(NSString*)host
-             completionHandler:(StatusQueryHandler)completionHandler {
-  base::ScopedCFTypeRef<SecTrustRef> trust(
-      web::CreateServerTrustFromChain(certChain, host));
+    querySSLStatusForTrust:(base::ScopedCFTypeRef<SecTrustRef>)trust
+                      host:(NSString*)host
+         completionHandler:(StatusQueryHandler)completionHandler {
   [_certVerificationController querySSLStatusForTrust:std::move(trust)
                                                  host:host
                                     completionHandler:completionHandler];
 }
 
 - (void)SSLStatusUpdater:(CRWSSLStatusUpdater*)SSLStatusUpdater
     didChangeSSLStatusForNavigationItem:(web::NavigationItem*)navigationItem {
   web::NavigationItem* currentNavigationItem =
       self.webState->GetNavigationManager()->GetLastCommittedItem();
   if (navigationItem == currentNavigationItem) {
@@ skipping 382 matching lines @@
   }
 
   return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
 }
 
 - (NSString*)refererFromNavigationAction:(WKNavigationAction*)action {
   return [action.request valueForHTTPHeaderField:@"Referer"];
 }
 
 @end