Support different aspect ratios based on keyboard orientation.

BUG=336605, 349001

Review URL: https://codereview.chromium.org/194623007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256671 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256671