[PATCH 2/2] protocol: Add buffer_scale to wl_surface and wl_output

[Bill Spitzak]

Pekka Paalanen wrote:

> You cannot get an identity by multiplying real-valued transformations
> together, other than by accident.

This is why I propose sending the inverse of the matrix, so the identity 
can be checked accurately. It also happens that the inverse matrix is 
the same matrix that is needed to tell cairo to draw the image correctly.