Move remove(All)Client(s)FromCache to RenderSVGResourceContainer

These methods are never called on something that is only RenderSVGResource.

BUG=420022

Review URL: https://codereview.chromium.org/634593002

git-svn-id: svn://svn.chromium.org/blink/trunk@183299 bbb929c8-8fbe-4397-9dbb-9b2b20218538