AW: enable WebViewTest.testJavascriptInterfaceCustomPropertiesClearedOnReload

No change to logic, this just enables a (passing) CTS test.

This CTS test was fixed chromium-side (http://crrev/c/886122), although
the test was also modified CTS-side (http://aosp/596153). Either way, we
can enable it.

Bug: 800941
Bug: 767847
Bug: 765873
Test: android_webview/tools/run_cts.py \
Test: -f=WebViewTest#testJavascriptInterfaceCustomPropertiesClearedOnReload
Test: (on L, M, N, O)
Change-Id: Ibaaa409507d2412c50d26f6225bffee192efa999
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1512592
Reviewed-by: Changwan Ryu <changwan@chromium.org>
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#639212}
1 file changed