Fix incorrect include in RenderLayerRepainter.h from r158725

TBR=leviw@chromium.org

Review URL: https://codereview.chromium.org/25668006

git-svn-id: svn://svn.chromium.org/blink/trunk@158730 bbb929c8-8fbe-4397-9dbb-9b2b20218538