The legacy SVG engine always had to perform relayouts when the transform
of an element changed (up to the containing block, stopping at RenderSVGRoot
boundary in case of mixed SVG/HTML documents). Container position and sizes
were affected by the transformations of the descendants. That's no longer the 
case in LBSE, which follows CSS/HTML style of making transformations a paint
effect, not inducing costly relayouts.
    
However this only works if SVG <text> elements are not involved: SVG text
always needs a relayout, as the "screen font size scaling factor" depends on
the CTM of the transformed element (all transformations from target element
up to RenderSVGRoot enter the calculation).

The patch will present a solution for that, giving us transform updates
without relayouts for everything except text, which is a good start.