Added specialization for bool Array which packs each element into a single bit.

Included some simple tests.

R=darin@chromium.org

Review URL: https://codereview.chromium.org/76963002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239330 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239330