OS: Mac OSX 10.9
What steps will reproduce the problem?
1. Load a page like http://en.wikipedia.org/wiki/Haiku
2. Reload a few times, or change tabs a few times (not exactly sure)
I expect the text to always be rendered in the font specified by CSS.
For some reason, the text is occasionally rendered in a serif font.
Sometimes, the font chosen in the CSS will reappear, but sometimes the unexpected sans-serif font will persist for a while.
See this video that demonstrates the problem: https://docs.google.com/file/d/0B0Z8In_MZG_FTG1kSUVYaXFoajQ/edit
This is strange on the Wikipedia Haiku page because if you look at the font stack, it is font-family: sans-serif; and so the serif isn't even on the font stack.