Android WebView: add sfntly to deps whitelist.

We are now merging sfntly to Android; add it to the whitelist for the
android_aosp bot.

BUG=
NOTRY=true

Review URL: https://codereview.chromium.org/82253002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236647 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236647