text-transform causes incorrect text placement in svg

Override originalText method in RenderSVGInlineText so
that RenderText::transformText uses it and gets the
text with SVG whitespace rules applied.

BUG=327606

Review URL: https://codereview.chromium.org/688023002

git-svn-id: svn://svn.chromium.org/blink/trunk@184655 bbb929c8-8fbe-4397-9dbb-9b2b20218538