Revert "Re-enabling Cross Origin Verification."

This reverts commit 5e2fc13c.

Reason for revert: Discovered that this is flaky under Windows and Linux.memory.  Will reproduce there.

Original change's description:
> Re-enabling Cross Origin Verification.
> 
> I've run this test using the Linux Release (with dcheck) 1000 times locally,
> and run 3 dry runs here.  I haven't been able to reproduce the flakiness
> observed initially.  I'm unsure if there was an underlying issue that was fixed
> or if I need to run on some additional architecture.  I plan to re-enable this
> and monitor the run tracker so I have a better idea how to address the
> flakiness if it still exists.
> 
> Bug: 874443
> Change-Id: Ic3a839fd28a105b1b761ddffca5363803b357cc9
> Reviewed-on: https://chromium-review.googlesource.com/1203933
> Reviewed-by: Charlie Harrison <csharrison@chromium.org>
> Commit-Queue: Eric Robinson <ericrobinson@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#588858}

TBR=csharrison@chromium.org,ericrobinson@chromium.org

Change-Id: I68c86ba816e4e555eee18fc3e744542d80cf7ec2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 874443
Reviewed-on: https://chromium-review.googlesource.com/1209983Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Commit-Queue: Eric Robinson <ericrobinson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589147}

chrome/browser/subresource_filter/ad_tagging_browsertest.cc

@@ -222,7 +222,8 @@ 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.