Re-enable WebstoreProviderTest on all platforms.
No evidence that these are no longer flaky, but we couldn't diagnose
this at the time and it's bad to keep them disabled. Re-enabling (at
least temporarily) will allow us to determine whether it is still flaky
and give us some more data points.
(Note: Ideally, these would be unit tests, not multi-process browser
tests, but there is too much multi-process logic in the code-under-test,
including the caching, the network server and URL fetching, and the JSON
decoding. Converting to a unit test requires a non-trivial refactor of
the code under test.)
BUG=246136
Review URL: https://codereview.chromium.org/
1125413004
Cr-Commit-Position: refs/heads/master@{#329096}