Added |-cancelJavaScriptDialogsForWebController:| to UI delegate.

ios/web/web_state/ui/crw_wk_web_view_web_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/web_state/ui/crw_wk_web_view_web_controller.h"
 
 #import <WebKit/WebKit.h>
 
 #include "base/containers/mru_cache.h"
 #include "base/ios/ios_util.h"
@@ skipping 871 matching lines @@
   base::WeakNSObject<CRWWKWebViewWebController> weakSelf(self);
   id crashHandler = ^{
     [weakSelf webViewWebProcessDidCrash];
   };
   return [[CRWWKWebViewCrashDetector alloc] initWithWebView:webView
                                                crashHandler:crashHandler];
 }
 
 - (void)webViewWebProcessDidCrash {
   _webProcessIsDead = YES;
-  if ([self.delegate respondsToSelector:
-          @selector(webControllerWebProcessDidCrash:)]) {
+  SEL cancelDialogsSelector =
+      @selector(cancelJavaScriptDialogsForWebController:);
+  if ([self.UIDelegate respondsToSelector:cancelDialogsSelector])
+    [self.UIDelegate cancelJavaScriptDialogsForWebController:self];
+  SEL rendererCrashSelector = @selector(webControllerWebProcessDidCrash:);
+  if ([self.delegate respondsToSelector:rendererCrashSelector])
     [self.delegate webControllerWebProcessDidCrash:self];
-  }
 }
 
 - (void)queryPageReferrerPolicy:(void(^)(NSString*))responseHandler {
   DCHECK(responseHandler);
   [self evaluateJavaScript:@"__gCrWeb.getPageReferrerPolicy()"
        stringResultHandler:^(NSString* referrer, NSError* error) {
       DCHECK_NE(error.code, WKErrorJavaScriptExceptionOccurred);
       responseHandler(!error ? referrer : nil);
   }];
 }
@@ skipping 971 matching lines @@
         runJavaScriptTextInputPanelWithPrompt:prompt
                                   defaultText:defaultText
                                    requestURL:requestURL
                             completionHandler:completionHandler];
   } else if (completionHandler) {
     completionHandler(nil);
   }
 }
 
 @end