Mark test_user_timing_measure_navigation_timing.htm as flaky

Fixes incorrect marking as flaky in
https://codereview.chromium.org/398423005, which forgot that the
FlakyTests file is auto-generated.

BUG=395127
TBR=tonyg@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/400223003

git-svn-id: svn://svn.chromium.org/blink/trunk@178452 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/TestExpectations

@@ -1326,3 +1326,6 @@ crbug.com/392764 [ Linux ] webaudio/distance-linear.html [ Pass Failure ]
 crbug.com/395103 [ Linux ] compositing/overflow/scroll-parent-with-non-stacking-context-composited-ancestor.html [ NeedsRebaseline ]
 crbug.com/395103 [ Linux ] virtual/gpu/compositedscrolling/overflow/scroll-parent-with-non-stacking-context-composited-ancestor.html [ NeedsRebaseline ]
 crbug.com/395103 [ Linux ] virtual/softwarecompositing/overflow/scroll-parent-with-non-stacking-context-composited-ancestor.html [ NeedsRebaseline ]
+
+# Flaky
+crbug.com/395127 http/tests/w3c/webperf/approved/UserTiming/test_user_timing_measure_navigation_timing.htm [ Failure Pass ]