Disable flaky MetricsWebContentsObserverTest.TimingOrderError

TBR=csharrison@chromium.org

Bug: 1011203
Change-Id: Ie9807b09fb16726f117c02507a3a200d22acfe0f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1839311Reviewed-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@{#702698}

components/page_load_metrics/browser/metrics_web_contents_observer_unittest.cc

@@ -487,7 +487,7 @@ TEST_F(MetricsWebContentsObserverTest, NullNavigationStartError) {
       page_load_metrics::internal::INVALID_NULL_NAVIGATION_START, 1);
 }
 
-TEST_F(MetricsWebContentsObserverTest, TimingOrderError) {
+TEST_F(MetricsWebContentsObserverTest, DISABLED_TimingOrderError) {
   mojom::PageLoadTiming timing;
   page_load_metrics::InitPageLoadTimingForTest(&timing);
   timing.navigation_start = base::Time::FromDoubleT(1);