sheriff: Disable sampling-native-profile-blink-gc.js; flaky on linux

https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Tests/74067

TBR=alph@chromium.org

Bug: 905772
Change-Id: Ibd7635ff2a66eb387443775210439c167a8aa14f
Reviewed-on: https://chromium-review.googlesource.com/c/1354743Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612047}

third_party/blink/web_tests/TestExpectations

@@ -5743,3 +5743,5 @@ crbug.com/906320 [ Mac10.13 ] virtual/site-isolated-code-cache/http/tests/devtoo
 crbug.com/908276 [ Mac ] external/wpt/webstorage/storage_setitem.html [ Pass Timeout ]
 crbug.com/908347 [ Mac ] media/autoplay/webaudio-audio-context-resume.html [ Failure Pass ]
 
+# Sheriff 2018-11-29
+crbug.com/905772 [ Linux ] inspector-protocol/memory/sampling-native-profile-blink-gc.js [ Failure Pass ]