[zoom] Smooth the scaling of fonts when zooming
[zoom] Smooth the scaling of fonts when zooming

Capture font size when gesture begins and correctly
update scale based off that until gesture ends.

Test plan:
1) hold Ctrl and scroll the mouse wheel in then out
in a single motion
2) notice zooming continues in initial direction
and accelerates towards the min or max

With patch it will adjust more smoothly and also
match the current zoom of the gesture.

@fix

godfath3r/terminology,godfath3r/terminology,godfath3r/terminology