HUD view position broken in PDF Embed API when container is scrolling

When the PDF Embed API is rendered into an element within a container that has an `overflow-y: scroll; ` property, the HUD view positioning breaks when scrolling. Instead of remaining positioned at the bottom, it seems to scroll up together with the first page of the document (see attached screen capture). This happens when the embed mode is set to  `IN_LINE` and any container around it has a fixed height set.

The positioning seems to be correctly reset after scrolling once a browser zoom event is triggered, however it will be incorrect again once the user proceeds to scroll again.

Steps to reproduce:

1.  Create a div container that has a fixed height and an `overflow-y: scroll` property (also happens with `auto`).
2.  Use the Adobe PDF Embed API to render any PDF into an element within that div container using in-line embed mode.
3.  Scroll within the PDF.