Version of Google Chrome (Wrench-> About Google Chrome): 64.0.3282.41 (Official build) beta (64 bits)
Chrome we tested on: Dell Chromebook 13 7310 (Lulu)


Steps to reproduce:

1) In the display options (chrome://settings/display), set the secondary monitor above the primary monitor (Screenshot provided)
2) Open the play store or any android app
3) Drag the window to the external monitor, if you move the window above the primary monitor limit, the app window will become transparent.

Screenshots/video and logs: https://drive.google.com/open?id=16FQiBnZQsiYMzuC7oFJn2Y4cqDlkyB81