Remove clipRect parameter from LayerPainter::applyRoundedRectClips().

It was only used to check if there was a radius involved, which is easy
enough, and even sensible (since we can then avoid calling this method
at all in most cases - after all, it's not like border radius is
something you set on every other element), to check before calling the
method.

Additionally, this made it pretty obvious that calling this from
paintTransformedLayerIntoFragments() was rather useless, since clipRect
there wasn't a ClipRect but a LayoutRect (which knows nothing about
radii).

R=chrishtr@chromium.org

Review URL: https://codereview.chromium.org/705303004

git-svn-id: svn://svn.chromium.org/blink/trunk@185086 bbb929c8-8fbe-4397-9dbb-9b2b20218538