Allow user script install by dragging onto chrome://extensions/.
Because otherwise, when off-store extension install is disabled,
there is no way to install user scripts.
BUG=55584
TEST=Run chrome with --enable-off-store-extension-install=0, navigate to a .user.js file. Should see error. Now download that file and drag onto chrome://extensions/. Should be offered a drop target, and install should proceed when dropped.
Review URL: https://chromiumcodereview.appspot.com/10449008
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@139640 0039d316-1c4b-4281-b951-d872f2087c98
2 files changed
