Disable flaky AdSamplerTriggerTest.PageWithNoAds

TBR=lpz@chromium.org

Bug: 1010783
Change-Id: Id166287895b8683cbdee68946ba600be4edbcaa5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1837320Reviewed-by: Yoichi Osato <yoichio@chromium.org>
Commit-Queue: Yoichi Osato <yoichio@chromium.org>
Auto-Submit: Yoichi Osato <yoichio@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702326}

components/safe_browsing/triggers/ad_sampler_trigger_unittest.cc

@@ -133,7 +133,7 @@ TEST_F(AdSamplerTriggerTest, TriggerDisabledBySamplingFrequency) {
                                       NO_SAMPLE_AD_SKIPPED_FOR_FREQUENCY, 2);
 }
 
-TEST_F(AdSamplerTriggerTest, PageWithNoAds) {
+TEST_F(AdSamplerTriggerTest, DISABLED_PageWithNoAds) {
   // Make sure the trigger doesn't fire when there are no ads on the page.
   CreateTriggerWithFrequency(/*denominator=*/1);