overviewControls: Use ClutterActor's translation-x
Instead of reimplementing translation-x
as a relayout. It still looks
the same but no longer incurs relayouts during the animation which
reduces render time significantly.
When combined with !936 (merged) this halves the render time for overview animations on my machine, from around 13ms to 6ms.
Related to: #1271 (closed)
Edited by Jeff Fortin