Remove Aero Peek Tabs code.

BUG=8036
TEST=Checked --enable-aero-peek-tabs does not take effect

Review URL: http://codereview.chromium.org/10368027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@135583 0039d316-1c4b-4281-b951-d872f2087c98
7 files changed