Note that it's extremely hard to find a treasure chest in the new zones, especially if you're playing during peak hours. Treasure hunting is recommended for early morning or late at night when most players are offline.
To ease your search, I recommend you to download Gathermate2, Gathermate2_data and Routes addons. Gatermate shows the treasure chests on your maps and with routes you can create a nice route that connects all chests it knows of, minimizing your time spent searching for the chests.
Here's examples how it will look.
Tip: I've seen no more than one chest per zone in Cataclysm zones.
★ Check the Elite Gold Making page for the best gold making tricks ★
★ Use the automated gold making addon and make 30,000 gold a day ★
★ Read the Most Secret Gold Making Tricks that even I cannot mention! ★
★ Level alts & professions. 1-90 in 2½ days is the record with this addon ★