Caged/d3-tip — pull request #44 by surjikal (2014-02-03 19:33:21+00:00)
Title: Correctly detect `document.documentElement`.

Before, if the `document.documentElement.scrollTop` or `document.documentElement.scrollTop` was `0`, the condition evaluated to false and the scroll value was fetched from `document.body` instead. This raised a warning in chrome. Now, we first find the available scroll element and then get its scroll value.