Convert message_center_unittests to run exclusively on Swarming

5 configs already ran on Swarming
8 used to run locally and were converted:
- chromium.chromiumos.json: Linux ChromiumOS Ozone Tests (1)
- chromium.chromiumos.json: Linux ChromiumOS Tests (1)
- chromium.chromiumos.json: Linux ChromiumOS Tests (dbg)(1)
- chromium.memory.json: Linux Chromium OS ASan LSan Tests (1)
- chromium.webkit.json: Linux ChromiumOS Tests (1)
- chromium.webkit.json: Linux ChromiumOS Tests (dbg)(1)
- chromium.win.json: Win 7 Tests x64 (1)
- chromium.win.json: Win7 Tests (1)

Ran:
  ./manage.py --convert message_center_unittests

R=dpranke@chromium.org
BUG=98637

Review URL: https://codereview.chromium.org/1204413002

Cr-Commit-Position: refs/heads/master@{#336260}
4 files changed