Disable test for upcoming DevTools change

Required for https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2215850

R=sigurds@chromium.org

Bug: 1011811
Change-Id: I818c2e72be4151674a9bedf4d03935fec81296a6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2216251
Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>
Auto-Submit: Tim van der Lippe <tvanderlippe@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774576}

third_party/blink/web_tests/TestExpectations

@@ -5901,3 +5901,6 @@ crbug.com/1088007 virtual/gpu/fast/canvas/OffscreenCanvas-MessageChannel-transfe
 
 # Sheriff 2020-06-03
 crbug.com/1007228 [ Mac10.13 ] external/wpt/fullscreen/api/element-request-fullscreen-and-move-to-iframe-manual.html [ Pass Failure ]
+
+# Disabled for landing DevTools change
+crbug.com/1011811 http/tests/devtools/persistence/automapping-sourcemap.js [ Pass Failure ]