Don't use RenderStyle::clone unless there is actually a RenderObject to attach the cloned style to.
Don't use RenderStyle::clone unless there is actually a RenderObject to attach the cloned style to.

Non-renderer-based elements such as optGroup do not have renderers.
BUG=348330
R=esprehn@chromium.org

Review URL: https://codereview.chromium.org/185293011

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@168394 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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