Rename Repaint to paintInvalidation in svg, part 2.

Apparently you can spell words with uppercase characters as well as
lower case characters.

BUG=338691

Review URL: https://codereview.chromium.org/468933002

git-svn-id: svn://svn.chromium.org/blink/trunk@180185 bbb929c8-8fbe-4397-9dbb-9b2b20218538