Amazing! Now that I know the term to search for, I'm certain that this is the misfeature that aggravates me so. My AOSP browser (which is 4.0.3) doesn't have this problem. I like the comment in the webkit bug discussing it: "In terms of status, this is shipping in stable Chrome for Android with acceptable quality." Ugh.
I thought it was something wrong with my CM build, or maybe because I didn't install gapps (Google's proprietary apps). I'm amazed to find the developers call this acceptable.