Get rid of recent win7/win10 chromium_win_gtests split again.

Undoes the split added in https://chromium-review.googlesource.com/1081627
The motivation for that split was that we don't have capacity to run
the test on both the win7 and win10 default cq bots.
Use test_suite_exceptions.pyl to not run the tests on the win7 cq bot.

This adds the test to the clang tot bots and some more main waterfall
win bots.

Bug: 818832,839419,843511
Change-Id: I550d01b33695bf07dea3b97a4bf6a0d8b3f404f4
Reviewed-on: https://chromium-review.googlesource.com/1099135
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567353}
6 files changed