Enable dictionary sync by default

This CL enables dictionary sync by default on all platforms except Android and
Mac, which do not use the Chrome custom spelling dictionary file.

BUG=72910


Review URL: https://chromiumcodereview.appspot.com/12096116

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@181430 0039d316-1c4b-4281-b951-d872f2087c98
14 files changed