Turn on the alternate caption button style by default.
The alternate caption button style
- Has a dedicated minimize button
- Does not have a help bubble for the maximize button
- Crossfades the minimize buttons into buttons for snapping left and right after pressing and holding the size button 

BUG=None
TEST=None

Review URL: https://codereview.chromium.org/183753002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254496 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 254496