Drop non-standard user gesture requirement from notification.requestPermission

BUG=274284
R=jww@chromium.org,felt@chromium.org,atwilson@chromium.org

Review URL: https://codereview.chromium.org/267363008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@270601 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed