Add missing comma in WATCHLIST
This patch adds missing comma in WATCHLIST after
0af49ad54149ee0c13b6e8b87d0c66a4b5d79c9f and serves to fix the following error:
```
$ git cl upload --send-mail
Using 50% similarity for rename/copy detection. Override with --similarity.
ERROR:root:Cannot parse /home/ilia/p/chromium/src/WATCHLISTS. invalid syntax (<string>, line 928)
Running presubmit upload checks ...
[...]
```
BUG=
TEST=
R=ben@chromium.org,brettw@chromium.org,nyquist@chromium.org
Review URL: https://codereview.chromium.org/
1345313002
Cr-Commit-Position: refs/heads/master@{#349369}