Disable flaky testRegularPlusIncognitoCheck test.

Bug: 842999
Change-Id: I97a64b1aa77c2991e0b20e80e985cbd4f7012e02
Tbr: tedchoc@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/1060108
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Bryan McQuade <bmcquade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558790}

chrome/android/javatests/src/org/chromium/chrome/browser/metrics/UkmTest.java

@@ -16,6 +16,7 @@ import org.junit.runner.RunWith;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.CallbackHelper;
 import org.chromium.base.test.util.CommandLineFlags;
+import org.chromium.base.test.util.DisabledTest;
 import org.chromium.base.test.util.RetryOnFailure;
 import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.browsing_data.BrowsingDataType;
@@ -95,7 +96,7 @@ public class UkmTest {
 
     @Test
     @SmallTest
-    @RetryOnFailure
+    @DisabledTest // TODO(https://crbug.com/842999): Reenable after unflaking.
     public void testRegularPlusIncognitoCheck() throws Exception {
         // Keep in sync with UkmBrowserTest.RegularPlusIncognitoCheck in
         // chrome/browser/metrics/ukm_browsertest.cc.