Don't consider the viewBox in SVGSVGElement::selfHasRelativeLengths()
Don't consider the viewBox in SVGSVGElement::selfHasRelativeLengths()

This CL removes the check for a viewBox value in said method.
The viewBox will not be affected by changes to the viewport(s) of
its ancestor(s).
And will not use hasAttribute for SVG values that can animate.

BUG=235256

Review URL: https://codereview.chromium.org/1082723002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@193949 bbb929c8-8fbe-4397-9dbb-9b2b20218538

smishenk/blink-crosswalk,Bysmyyr/blink-crosswalk,Pluto-tv/blink-crosswalk,PeterWangIntel/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Bysmyyr/blink-crosswalk,Pluto-tv/blink-crosswalk,PeterWangIntel/blink-crosswalk,XiaosongWei/blink-crosswalk,Pluto-tv/blink-crosswalk,Bysmyyr/blink-crosswalk,smishenk/blink-crosswalk,XiaosongWei/blink-crosswalk,XiaosongWei/blink-crosswalk,XiaosongWei/blink-crosswalk,Bysmyyr/blink-crosswalk,Pluto-tv/blink-crosswalk,PeterWangIntel/blink-crosswalk,smishenk/blink-crosswalk,smishenk/blink-crosswalk,PeterWangIntel/blink-crosswalk,Pluto-tv/blink-crosswalk,smishenk/blink-crosswalk,XiaosongWei/blink-crosswalk,Bysmyyr/blink-crosswalk,XiaosongWei/blink-crosswalk,smishenk/blink-crosswalk,Bysmyyr/blink-crosswalk,PeterWangIntel/blink-crosswalk,XiaosongWei/blink-crosswalk,Pluto-tv/blink-crosswalk,Bysmyyr/blink-crosswalk,PeterWangIntel/blink-crosswalk,Pluto-tv/blink-crosswalk,PeterWangIntel/blink-crosswalk,PeterWangIntel/blink-crosswalk,XiaosongWei/blink-crosswalk,XiaosongWei/blink-crosswalk,Bysmyyr/blink-crosswalk,smishenk/blink-crosswalk,PeterWangIntel/blink-crosswalk,smishenk/blink-crosswalk,Bysmyyr/blink-crosswalk,PeterWangIntel/blink-crosswalk,smishenk/blink-crosswalk,smishenk/blink-crosswalk,XiaosongWei/blink-crosswalk,Bysmyyr/blink-crosswalk,Pluto-tv/blink-crosswalk