[SVG] Remove "New" prefix from properties implementation.

All old SVGProperties implementations are now all removed. The "New" prefix for distinguishing two implementations are no longer needed.

Changes automatically generated from: sed -i 's/NewSVG/SVG/g' `find . -name \*.cpp -or -name \*.h`

BUG=349370

Review URL: https://codereview.chromium.org/208133002

git-svn-id: svn://svn.chromium.org/blink/trunk@169737 bbb929c8-8fbe-4397-9dbb-9b2b20218538