I'm still facing the same problems with the missing autofocus. For some devices it works out of the box, like the HTC one mini, but for the most it does not. There is actually an open issue about that in the Chrome-Browser for Android (https://code.google.com/p/chromium/issues/detail?id=343894)

It would help a lot to get continous autofocus working in the browsers. Especially with barcodes, since their size requires the camera to be really close.