Mark target-reloaded-after-crash.js as flaky

This test has been flaky since it was introduced. Probably due to the
same issue as issue 1046784.

TBR=yurys@chromium.org

Bug: 1046784
Change-Id: I02b4e0c7c39c6123b1a6f0db70f1dacf6c7cbd05
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2230913Reviewed-by: Yi Gu <yigu@chromium.org>
Commit-Queue: Yi Gu <yigu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#775229}

third_party/blink/web_tests/TestExpectations

@@ -5634,6 +5634,7 @@ crbug.com/1046784 http/tests/devtools/bindings/navigator-frame-attach-detach.js
 crbug.com/1046784 http/tests/devtools/forced-layout-in-microtask.js [ Pass Timeout ]
 crbug.com/1046784 http/tests/devtools/application-panel/resources-panel-iframe-idb.js [ Pass Timeout ]
 crbug.com/1046784 http/tests/devtools/a11y-axe-core/sources/scope-pane-a11y-test.js [ Pass Timeout ]
+crbug.com/1046784 http/tests/inspector-protocol/service-worker/target-reloaded-after-crash.js [ Pass Timeout ]
 
 # Sheriff 2020-01-28
 crbug.com/1046201 [ Mac ] fast/forms/calendar-picker/calendar-picker-appearance-zoom125.html [ Pass Failure ]