Cast: Added a EncodingEventSubscriber to cast sender app.

- Logs encoded uncompressed raw events for the first X seconds to a file path Y, where X and Y
  can be specified by the user.
- Also outputs some basic stats.

Review URL: https://codereview.chromium.org/162103002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251972 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251972
Cast: Implemented relative RTP timestamp in EncodingEventSubscriber.

- RTP timestamps in the maps of EncodingEventSubscribers (map keys, rtp timestamp fields in protos) are now relative to the first RTP timestamp seen since last Reset().
- The two GetXXXEventsAndReset() functions have been combined into one. In addition, it will now return the first RTP timestamp seen since the last Reset(). It will also reset the first RTP timestamp seen.
- There are two motivations for this change:
-- 1. RTP timestamps wrap around easily - around every 12 hours or so. If we do not use relative RTP timestamps, the ordering in the map, as well as general order of the events by frame, will be messed up.
-- 2. Using relative values will be more compact in variable-length encoding of the RTP timestamp fields.

Review URL: https://codereview.chromium.org/168933002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251973 0039d316-1c4b-4281-b951-d872f2087c98
Listen for all input events on copies capability text field.

BUG=264124

Review URL: https://codereview.chromium.org/171433002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251974 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251973
SVN changes up to revision 251974