Mark devtools tests as flaky

debugger-ui/inline-scope-variables.js
was timing out but were only marked as Failure. Marking as timing
out as well.

Bug: 1149734,1150458
Change-Id: I71c6333bcfc6bb015285479a2ada156884e4b472
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2645369
Commit-Queue: Nina Satragno <nsatragno@chromium.org>
Auto-Submit: Nina Satragno <nsatragno@chromium.org>
Reviewed-by: Katie Dektar <katie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#846367}

third_party/blink/web_tests/TestExpectations

@@ -5705,7 +5705,7 @@ crbug.com/1152088 [ Mac10.13 Debug ] fast/dom/cssTarget-crash.html [ Pass Timeou
 crbug.com/1149734 http/tests/devtools/sources/source-frame-toolbar-items.js [ Pass Failure Timeout ]
 crbug.com/1149734 http/tests/devtools/sources/debugger-frameworks/frameworks-sourcemap.js [ Pass Failure ]
 crbug.com/1149734 http/tests/devtools/sources/debugger-ui/continue-to-location-markers.js [ Pass Failure ]
-crbug.com/1149734 http/tests/devtools/sources/debugger-ui/inline-scope-variables.js [ Pass Failure ]
+crbug.com/1149734 http/tests/devtools/sources/debugger-ui/inline-scope-variables.js [ Pass Failure Timeout ]
 
 #Sheriff 2020-11-24
 crbug.com/1152496 [ Win ] virtual/oopr-canvas2d/fast/canvas/canvas-composite-shadow.html [ Pass Timeout ]