iOS Web Shell: Implemented warning dialog for invalid SSL certs.

ios/web/shell/view_controller.mm

 // Copyright 2014 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/shell/view_controller.h"
 
 #include "base/mac/objc_property_releaser.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 275 matching lines @@
 
 - (void)webPageOrderedClose {
 }
 - (void)goDelta:(int)delta {
 }
 - (void)openURLWithParams:(const web::WebState::OpenURLParams&)params {
 }
 - (BOOL)openExternalURL:(const GURL&)url {
   return NO;
 }
+
 - (void)presentSSLError:(const net::SSLInfo&)info
            forSSLStatus:(const web::SSLStatus&)status
             recoverable:(BOOL)recoverable
                callback:(SSLErrorCallback)shouldContinue {
+  UIAlertController* alert = [UIAlertController
+      alertControllerWithTitle:@"Your connection is not private"
+                       message:nil
+                preferredStyle:UIAlertControllerStyleActionSheet];
+  [alert addAction:[UIAlertAction actionWithTitle:@"Go Back"
+                                            style:UIAlertActionStyleCancel
+                                          handler:^(UIAlertAction*) {
+                                            shouldContinue(NO);
+                                          }]];
+
+  if (recoverable) {
+    [alert addAction:[UIAlertAction actionWithTitle:@"Continue"
+                                              style:UIAlertActionStyleDefault
+                                            handler:^(UIAlertAction*) {
+                                              shouldContinue(YES);
+                                            }]];
+  }
+  [self presentViewController:alert animated:YES completion:nil];
 }
+
 - (void)presentSpoofingError {
 }
 - (void)webLoadCancelled:(const GURL&)url {
 }
 - (void)webDidUpdateHistoryStateWithPageURL:(const GURL&)pageUrl {
 }
 - (void)webController:(CRWWebController*)webController
     retrievePlaceholderOverlayImage:(void (^)(UIImage*))block {
 }
 - (void)webController:(CRWWebController*)webController
@@ skipping 15 matching lines @@
 - (void)webDidPrepareForGoBack {
 }
 - (int)downloadImageAtUrl:(const GURL&)url
             maxBitmapSize:(uint32_t)maxBitmapSize
                  callback:
                      (const web::WebState::ImageDownloadCallback&)callback {
   return -1;
 }
 
 @end