Is it safe to cook a steak that was left out (raw) for 7 hours?
It's perfectly safe to cook it, as long as you don't plan to eat it.  The exception is if the water was at or below fridge temperature to begin with.  When food temperature enters the "danger zone" of 40-140F/4-60C, there's a lag time of 2 hours before bacteria go into exponential replication.  Any longer, and the bacteria counts start to increase exponentially, doubling every 30 minutes to an hour.  With the bacteria counts, the risk of food poisoning increases exponentially.  7 hours is just beyond the pale.  

Beyond the time/temperature problem, there are 3 things everyone needs to know about food safety:


You cannot smell pathogens, just rancidity/spoilage.  With spoilage, your food is definitely unsafe to eat, but it may be dangerous long before it smells "off."
Cooking to ~165F/74C kills pathogenic bacteria. Different agencies and foods have slightly different temperatures, but most are at or below this temperature.
Cooking will NOT destroy toxins bacteria produce, so heavy cooking is not a solution to meat left out too long.  Staphylococcus aureus ("Staph"), chlostridium botulinum ("botulism"), Escheria coli ("E. coli"), and chlostridium perfringens all produce toxic chemicals, which are not destroyed by cooking.


If it was a very expensive steak, I'd be tempted to cut off the exterior and cook it heavily for myself only (would never dare serve to another).  But, for a simple round steak?  Bin it and buy another, it's not worth the risk.