Do not rewrite about urls to chrome:// for cetain renderer-initated loads

ios/web/web_state/ui/crw_web_controller.mm

Index: ios/web/web_state/ui/crw_web_controller.mm
diff --git a/ios/web/web_state/ui/crw_web_controller.mm b/ios/web/web_state/ui/crw_web_controller.mm
index ccd31a039220858dec9b95c4540a465aae73177c..edc3f53d1e78f8c322f74ce8e5c246ea0f83404a 100644
--- a/ios/web/web_state/ui/crw_web_controller.mm
+++ b/ios/web/web_state/ui/crw_web_controller.mm
@@ -1266,14 +1266,7 @@ const NSTimeInterval kSnapshotOverlayTransition = 0.5;
 - (GURL)currentURLWithTrustLevel:(web::URLVerificationTrustLevel*)trustLevel {
   DCHECK(trustLevel) << "Verification of the trustLevel state is mandatory";
   if (_webView) {
-    GURL url([self webURLWithTrustLevel:trustLevel]);
-    // Web views treat all about: URLs as the same origin, which makes it
-    // possible for pages to document.write into about:<foo> pages, where <foo>
-    // can be something misleading. Report any about: URL as about:blank to
-    // prevent that. See crbug.com/326118
-    if (url.scheme() == url::kAboutScheme)
-      return GURL(url::kAboutBlankURL);
-    return url;
+    return [self webURLWithTrustLevel:trustLevel];
   }
   // Any non-web URL source is trusted.
   *trustLevel = web::URLVerificationTrustLevel::kAbsolute;
@@ -2141,7 +2134,10 @@ registerLoadRequestForURL:(const GURL&)requestURL
          ![[_navigationStates lastAddedNavigation] isEqual:navigation] ||
          // invalid URL load
          (!_lastRegisteredRequestURL.is_valid() &&
-          _documentURL.spec() == url::kAboutBlankURL))
+          _documentURL.spec() == url::kAboutBlankURL) ||
+         // about URL was changed by WebKit (e.g. about:newtab -> about:blank)
+         (_lastRegisteredRequestURL.scheme() == url::kAboutScheme &&
+          currentURL.spec() == url::kAboutBlankURL))
       << std::endl
       << "currentURL = [" << currentURL << "]" << std::endl
       << "_lastRegisteredRequestURL = [" << _lastRegisteredRequestURL << "]";