Add yoshiki@ to filemanager WATCHLIST

And also remove yoshiki@ from the previous a11y and task_manager.

BUG=none
TBR=satorux@chromium.org
NOTRY=True

Review URL: https://codereview.chromium.org/149753012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250903 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250903