DevTools: gardening: mark http/tests/inspector/tracing as flaky.

BUG=420008
TBR=yurys@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/654483003

git-svn-id: svn://svn.chromium.org/blink/trunk@183592 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/TestExpectations

@@ -1435,6 +1435,7 @@ crbug.com/404494 [ Win ] http/tests/xmlhttprequest/xmlhttprequest-allowed-with-d
 crbug.com/421283 fast/html/marquee-scrollamount.html [ Pass Failure ]
 
 crbug.com/420008 [ Win ] inspector/tracing [ Pass Failure ]
+crbug.com/420008 [ Win ] http/tests/inspector/tracing [ Pass Failure ]
 crbug.com/420008 [ Win ] virtual/deferred/inspector/tracing [ Pass Failure ]
 crbug.com/420008 [ Win ] virtual/implsidepainting/inspector/tracing [ Pass Failure ]