Add a WATCHLIST for Source/heap and add haraken@ to it

TBR=abarth
NOTRY=true

Review URL: https://codereview.chromium.org/113823002

git-svn-id: svn://svn.chromium.org/blink/trunk@163766 bbb929c8-8fbe-4397-9dbb-9b2b20218538