I don't like to let women take control in the bedroom. My view is that what happens in bed determines the natural dynamic between a man and a woman, the one that influences her emotions in her everyday interactions with me. When a man thoroughly dominates a woman in bed, he feels in control of his relationship, and vice versa.
This happened once to me, a girlfriend of mine wanting to ride on top and talk in a dominant way to me, and even grabbed my arms and tried to hold them down, which was funny. I put an end to it quickly though, because it didn't feel good. Once I told her it was not on, she readily gave up on the idea and happily got dominated by me in all sorts of ways from then on.
I'm not entirely sure if it's a test or not, but even if it isn't, I think it still is. There are women who have naturally dominant personalities (such as this girlfriend, I believe it came from growing up in a female-dominated household) but all women still like to get dominated by a strong, masculine man.
My theory is that a woman is always ideally looking for a dominant man, but some of them have a higher threshold of submission, and can temporarily enjoy being dominant to a greater or lesser extent depending on their experiences with the opposite sex growing up. But in the end, I believe that for all women, being dominant for a long enough period of time leaves them confused and emotional, and makes them start looking for that ideal man again (which won't be you if she's used to dominating you).
So in the end, you're better off putting on the captain's cap right from the start.