Making media events bitless, freeing up a few event bits, since modern,
implementing browsers don't leak the way old ones did.

The following constants, marked as 'experimental', have been removed:
- com.google.gwt.user.client.Event.MEDIAEVENTS
- com.google.gwt.user.client.Event.ONCANPLAYTHROUGH
- com.google.gwt.user.client.Event.ONENDED
- com.google.gwt.user.client.Event.ONPROGRESS

Review at http://gwt-code-reviews.appspot.com/1447816

Review by: jlabanca@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10274 8db76d5a-ed1c-0410-87a9-c151d255dfc7
6 files changed