Bug 1458814: Mark some tests as failing with webrender. r=jrmuizel

The patches in this bug makes layout get more accurate values. That apparently
is confusing WebRender, which renders one more pixel height in some of the
rectangles.

I have no idea why and I couldn't repro out of the reftest harness. I suspect
something something blob invalidation, but...

MozReview-Commit-ID: A2slTJLfJBx

layout/reftests/svg/smil/style/reftest.list

@@ -116,18 +116,18 @@ fails == anim-css-strokedasharray-1.svg anim-css-strokedasharray-1-ref.svg # bug
 # in order to interpolate between pct and non-pct values, and we don't yet
 # support calc() for stroke-width & other SVG-specific properties. (Bug 1258270
 # for gecko, Bug 1386967 for stylo)
-== anim-css-strokewidth-1-by-pct-pct.svg      anim-css-strokewidth-1-ref.svg
-fails == anim-css-strokewidth-1-by-pct-px.svg       anim-css-strokewidth-1-ref.svg
-fails == anim-css-strokewidth-1-by-px-pct.svg       anim-css-strokewidth-1-ref.svg
-== anim-css-strokewidth-1-from-by-pct-pct.svg anim-css-strokewidth-1-ref.svg
-fails == anim-css-strokewidth-1-from-by-pct-px.svg  anim-css-strokewidth-1-ref.svg
-fails == anim-css-strokewidth-1-from-by-px-pct.svg  anim-css-strokewidth-1-ref.svg
-== anim-css-strokewidth-1-from-to-pct-pct.svg anim-css-strokewidth-1-ref.svg
-fails == anim-css-strokewidth-1-from-to-pct-px.svg  anim-css-strokewidth-1-ref.svg
-fails == anim-css-strokewidth-1-from-to-px-pct.svg  anim-css-strokewidth-1-ref.svg
-== anim-css-strokewidth-1-to-pct-pct.svg      anim-css-strokewidth-1-ref.svg
-fails == anim-css-strokewidth-1-to-pct-px.svg       anim-css-strokewidth-1-ref.svg
-fails == anim-css-strokewidth-1-to-px-pct.svg       anim-css-strokewidth-1-ref.svg
+== anim-css-strokewidth-1-by-pct-pct.svg                          anim-css-strokewidth-1-ref.svg
+fails == anim-css-strokewidth-1-by-pct-px.svg                     anim-css-strokewidth-1-ref.svg
+fails == anim-css-strokewidth-1-by-px-pct.svg                     anim-css-strokewidth-1-ref.svg
+fails-if(webrender) == anim-css-strokewidth-1-from-by-pct-pct.svg anim-css-strokewidth-1-ref.svg # bug 1459418
+fails == anim-css-strokewidth-1-from-by-pct-px.svg                anim-css-strokewidth-1-ref.svg
+fails == anim-css-strokewidth-1-from-by-px-pct.svg                anim-css-strokewidth-1-ref.svg
+fails-if(webrender) == anim-css-strokewidth-1-from-to-pct-pct.svg anim-css-strokewidth-1-ref.svg # bug 1459418
+fails == anim-css-strokewidth-1-from-to-pct-px.svg                anim-css-strokewidth-1-ref.svg
+fails == anim-css-strokewidth-1-from-to-px-pct.svg                anim-css-strokewidth-1-ref.svg
+fails-if(webrender) == anim-css-strokewidth-1-to-pct-pct.svg      anim-css-strokewidth-1-ref.svg # bug 1459418
+fails == anim-css-strokewidth-1-to-pct-px.svg                     anim-css-strokewidth-1-ref.svg
+fails == anim-css-strokewidth-1-to-px-pct.svg                     anim-css-strokewidth-1-ref.svg
 
 # 'stroke-width' property, from/by/to with em values
 == anim-css-strokewidth-1-by-px-em.svg        anim-css-strokewidth-1-ref.svg