Disable AdTaggingBrowserTest.VerifyCrossOriginWithoutNavigate

According to flakiness dashboard, this is flaky on all platform that is
running the test
https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=network_service_browser_tests&tests=AdTaggingBrowserTest.VerifyCrossOriginWithoutNavigate

TBR=wjmaclean@chromium.org
NOTRY=true

Bug: 874424
Change-Id: Ic737edd9bb502b4472feb0163f2f823f110a2174
Reviewed-on: https://chromium-review.googlesource.com/1175696Reviewed-by: Xida Chen <xidachen@chromium.org>
Commit-Queue: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583227}

chrome/browser/subresource_filter/ad_tagging_browsertest.cc

@@ -217,7 +217,8 @@ IN_PROC_BROWSER_TEST_F(AdTaggingBrowserTest, VerifySameOriginWithoutNavigate) {
       AdsPageLoadMetricsObserver::AdOriginStatus::kSame, 1);
 }
 
-IN_PROC_BROWSER_TEST_F(AdTaggingBrowserTest, VerifyCrossOriginWithoutNavigate) {
+IN_PROC_BROWSER_TEST_F(AdTaggingBrowserTest,
+                       DISABLED_VerifyCrossOriginWithoutNavigate) {
   base::HistogramTester histogram_tester;
 
   // Main frame.