Spectator's Chest
The Spectator's Chest, next to the Spectator's Chair is found at [24.2, 27.1] on the upper level of the eastern side of the Circle of Blood in northwest Frostfire Ridge. To get up top, enter the watchtower immediately southeast of the Circle of Blood arena, where Igrimar the Resolute was found, run up the ramp, then mount up and jump off to the north.
The chest contains 10-20x 
[Garrison Resources], 15x 
[Blackheart Grog], and a rapidly melting 
[Ice Stone]. When it melts, it triggers a boss warning:
- The Ice Stone has melted!
Apparently the Arena Spectator imbibed a little too much, as he is found on the ground beneath the chair.
Tracking quest
To check whether this chest has been looted, copy and paste this command into the chat window:
/run print(C_QuestLog.IsQuestFlaggedCompleted(33501))
If a "true" appears in the chat window, this chest has been looted; "false" indicates the opposite.
Patch changes
Patch 6.0.2 (2014-10-14): Added.