DevTools: mark http/tests/devtools/console/console-search.js as flaky on Leak bot

After marking the test from skip to pass / fail / timeout in
https://chromium-review.googlesource.com/c/chromium/src/+/845979,
we can see the test is only flaky on the Leak bot:
https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=webkit_layout_tests&tests=http/tests/devtools/console/console-search.js

Bug: 667560
Change-Id: I0734ef74c65bd067ce7f933ed488b37ecd24fb23
Reviewed-on: https://chromium-review.googlesource.com/847306Reviewed-by: Erik Luo <luoe@chromium.org>
Commit-Queue: Will Chen <chenwilliam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526535}

third_party/WebKit/LayoutTests/LeakExpectations

@@ -43,6 +43,7 @@ crbug.com/762353 external/wpt/beacon/headers/header-referrer-no-referrer.html [
 crbug.com/651742 external/wpt/content-security-policy/connect-src/connect-src-beacon-allowed.sub.html [ Leak Pass ]
 crbug.com/780386 external/wpt/html/dom/reflection-grouping.html [ Leak Pass ]
 crbug.com/796944 [ Linux ] synthetic_gestures/synthetic-pinch-zoom-gesture.html [ Leak Pass ]
+crbug.com/667560 [ Linux ] http/tests/devtools/console/console-search.js [ Leak Pass ]
 
 # -----------------------------------------------------------------
 # Not revert suspected CL as jam@ request, expected to be fixed soon.

third_party/WebKit/LayoutTests/TestExpectations

@@ -723,8 +723,6 @@ crbug.com/776656 virtual/incremental-shadow-dom/shadow-dom/slotted-pseudo-elemen
 
 # ====== IncrementalShadowDOM-only failures until here ======
 
-crbug.com/667560 http/tests/devtools/console/console-search.js [ Pass Failure Timeout ]
-
 crbug.com/667560 [ Debug ] http/tests/devtools/elements/styles-3/styles-change-node-while-editing.js [ Pass Failure ]
 crbug.com/778515 http/tests/devtools/elements/styles-3/styles-add-new-rule.js [ Pass Failure ]