[ios] Signal DidFinishLoad if target URL is invalid.

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 <objc/runtime.h>
 #include <stddef.h>
 
 #include <cmath>
@@ skipping 1309 matching lines @@
 // Load the current URL in a web view, first ensuring the web view is visible.
 - (void)loadCurrentURLInWebView {
   [self willLoadCurrentURLInWebView];
 
   // Clear the set of URLs opened in external applications.
   _openedApplicationURL.reset([[NSMutableSet alloc] init]);
 
   // Load the url. The UIWebView delegate callbacks take care of updating the
   // session history and UI.
   const GURL targetURL([self currentNavigationURL]);
-  if (!targetURL.is_valid())
+  if (!targetURL.is_valid()) {
+    [self didFinishWithURL:targetURL loadSuccess:NO];
     return;
+  }
 
   // JavaScript should never be evaluated here. User-entered JS should be
   // evaluated via stringByEvaluatingUserJavaScriptFromString.
   DCHECK(!targetURL.SchemeIs(url::kJavaScriptScheme));
 
   [self ensureWebViewCreated];
 
   [self loadRequestForCurrentNavigationItem];
 }
 
@@ skipping 2563 matching lines @@
   if ([MIMEType isEqualToString:@"text/html"] ||
       [MIMEType isEqualToString:@"application/xhtml+xml"] ||
       [MIMEType isEqualToString:@"application/xml"]) {
     return web::WEB_VIEW_DOCUMENT_TYPE_HTML;
   }
 
   return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
 }
 
 @end