with sync

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 4b3851642a5e02d492e6878998756f4ae43df959..5069bf8a9c98989cedc0195accce5485c856714b 100644
--- a/ios/web/web_state/ui/crw_web_controller.mm
+++ b/ios/web/web_state/ui/crw_web_controller.mm
@@ -4726,7 +4726,18 @@ const NSTimeInterval kSnapshotOverlayTransition = 0.5;
 }
 
 - (void)loadRequest:(NSMutableURLRequest*)request {
-  _latestWKNavigation.reset([[_webView loadRequest:request] retain]);
+  if ([[request URL] isFileURL]) {
+    NSURL* url = [request URL];
+    NSMutableArray* partsArray =
+        [NSMutableArray arrayWithArray:[url pathComponents]];
+    [partsArray removeLastObject];
+    _latestWKNavigation.reset([[_webView
+                    loadFileURL:url
+        allowingReadAccessToURL:[NSURL fileURLWithPathComponents:partsArray]]
+        retain]);
+  } else {
+    _latestWKNavigation.reset([[_webView loadRequest:request] retain]);
+  }
 }
 
 - (void)loadPOSTRequest:(NSMutableURLRequest*)request {