[Android] Set --optimize-for-size JavaScript flag for low-end devices

BUG=292928

Review URL: https://codereview.chromium.org/24210017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226198 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226198