GitLab

Allows developers to explicitly specify what accept types they would like to allow in their file selectors, as well as whether they allow all files as a last option.

BUG=133066
TEST=Test cases, manual testing

Review URL: https://chromiumcodereview.appspot.com/10692105

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@150515 0039d316-1c4b-4281-b951-d872f2087c98