GitLab

Add InputMethodMac class and update InputMethodFactory to create it.
It doesn't do anything for now. We plan to bridge NSTextInputClient calls
directly to the focused ui::TextInputClient object.

BUG=374077

Review URL: https://codereview.chromium.org/312523003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274636 0039d316-1c4b-4281-b951-d872f2087c98