The middle button is used to orbit, and it works. However, when I combine it with Shift to pan, it gets stuck to panning. Even after Shift key is released. To “release” this pan mode lock in, I must click on the browser address bar, and then on the content again.
This issue seems to only affect chrome under Linux (Version 54.0.2840.59 (64-bit)), I was unable to reproduce under Windows (Version 54.0.2840.59 (64-bit)).