[Nav Experiment] Temporarily disable broken NavigationTestCase test.

Bug: 905688
Change-Id: I11f0b6320ba8221139323a285199a5570afab429
Reviewed-on: https://chromium-review.googlesource.com/c/1338308Reviewed-by: Eugene But <eugenebut@chromium.org>
Commit-Queue: Danyao Wang <danyao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608526}

ios/chrome/browser/web/navigation_egtest.mm

@@ -12,6 +12,7 @@
 #import "ios/chrome/test/earl_grey/chrome_earl_grey.h"
 #import "ios/chrome/test/earl_grey/chrome_matchers.h"
 #import "ios/chrome/test/earl_grey/chrome_test_case.h"
+#include "ios/web/public/features.h"
 #import "ios/web/public/test/url_test_util.h"
 #include "net/test/embedded_test_server/http_request.h"
 #include "net/test/embedded_test_server/http_response.h"
@@ -603,6 +604,10 @@ std::unique_ptr<net::test_server::HttpResponse> WindowLocationHashHandlers(
 // Tests that navigating forward from NTP works when resuming from session
 // restore. This is a regression test for https://crbug.com/814790.
 - (void)testRestoreHistoryToNTPAndNavigateForward {
+  // TODO(crbug.com/905688): re-enable this test.
+  if (base::FeatureList::IsEnabled(web::features::kSlimNavigationManager))
+    EARL_GREY_TEST_DISABLED(@"Test disabled on SlimNavigationManager.");
+
   GREYAssertTrue(self.testServer->Start(), @"Test server failed to start.");
   const GURL destinationURL = self.testServer->GetURL(kSimpleFileBasedTestURL);
   [ChromeEarlGrey loadURL:destinationURL];