Disable flaky devtools tests

debugger-inline-values-frames.js and reveal-execution-line.js are
flaking across different bots.

TBR: tasak@google.com
Bug: 1149734
Change-Id: I17eda8a8f475aa98532771b122ef5d590a84c02b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2543085Reviewed-by: Thomas Guilbert <tguilbert@chromium.org>
Commit-Queue: Thomas Guilbert <tguilbert@chromium.org>
Auto-Submit: Thomas Guilbert <tguilbert@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828028}

third_party/blink/web_tests/TestExpectations

@@ -5995,3 +5995,7 @@ crbug.com/1130020 virtual/threaded-prefer-compositing/fast/scrolling/scrollbars/
 
 # DevTools roll
 crbug.com/1011811 http/tests/devtools/console/console-edit-expanded-tree.js [ Skip ]
+
+# Sheriff 2020-11-16
+crbug.com/1149734 http/tests/devtools/sources/debugger-ui/debugger-inline-values-frames.js [ Pass Failure ]
+crbug.com/1149734 http/tests/devtools/sources/debugger-ui/reveal-execution-line.js [ Pass Failure ]