Reland Web UI: Disable interactive_ui_tests on Windows, enable elsewhere

Some interactive_ui_tests were disabled on all platforms, but are in
fact only flaky on Windows due to https://crbug.com/711256. Re-enable
these tests on other platforms. Other Web UI tests are still enabled
but continuing to flake on Windows for the same reason; disable these
tests on Windows also.

Modification to original: Keep CrExtensionsOptionsPageTest.All disabled
on all platforms, since it appears to still be flaky.

Note: If tests begin flaking after this CL lands, please disable only
the flaky tests if possible, rather than reverting the entire CL, so
that the test coverage being restored by this CL can be retained.

Bug: 711256, 945630
Change-Id: I6a3026a9f152d29515c39a94fafe4c526096909c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1547958
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#647051}
9 files changed