Convert wm_unittests to run exclusively on Swarming

Convert wm_unittests to run exclusively on Swarming

0 configs already ran on Swarming
18 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.fyi.json: Linux Trusty
- chromium.fyi.json: Linux Trusty (dbg)
- chromium.linux.json: Linux Tests
- chromium.linux.json: Linux Tests (dbg)(1)
- chromium.linux.json: Linux Tests (dbg)(1)(32)
- chromium.memory.fyi.json: Linux ChromeOS MSan Tests
- chromium.memory.fyi.json: Linux MSan Tests
- chromium.memory.fyi.json: Linux TSan Tests
- chromium.webkit.json: Linux ChromiumOS Tests (1)
- chromium.webkit.json: Linux ChromiumOS Tests (dbg)(1)
- chromium.win.json: Vista Tests (1)
- chromium.win.json: Win 7 Tests x64 (1)
- chromium.win.json: Win7 Tests (1)
- chromium.win.json: Win7 Tests (dbg)(1)
- chromium.win.json: XP Tests (1)

Ran:
  ./manage.py --convert wm_unittests

R=sky@chromium.org,thakis@chromium.org
TBR=
BUG=98637

Review URL: https://codereview.chromium.org/1217473009

Cr-Commit-Position: refs/heads/master@{#336901}