Cast: Add missing enum and PacketEvent field to cast_messages.

Cast: Add missing enum and PacketEvent field to cast_messages.

Due to the event type refactoring landed earlier, an enum field
EventMediaType was added to PacketEvent. PacketEvent is transmitted
via IPC from browser to renderer so we need to add them to the IPC
definition as well.

Also fix compile in cast_sender_app.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=270262

[imcheng, 2014-05-12 21:03:23]

PTAL. This will need to be merged to M36 I think if branch point already
occurred.

[Alpha Left Google, 2014-05-13 05:32:47]

LGTM.

[dcheng, 2014-05-13 05:37:26]

Sorry, I'm in Zurich for BlinkOn atm. You should find another IPC reviewer if
you need this ASAP.

[imcheng, 2014-05-13 18:03:57]

+jschuh, could you please take a look at chrome/common/cast_messages.h? In
there, I added declaration for an enum field that was added to a struct in a
refactoring last week.

[jschuh, 2014-05-13 20:32:33]

ipc security lgtm. (notes: opaque enum used for logging)

[imcheng, 2014-05-13 20:39:21]

The CQ bit was checked by imcheng@chromium.org

[commit-bot: I haz the power, 2014-05-13 20:41:54]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/imcheng@chromium.org/279833003/40001

[commit-bot: I haz the power, 2014-05-14 00:14:15]

Change committed as 270262