Move common GC state update code out of paint-server application

All paint-server RenderSVGResources contain the same code to update the
GC state, transferring stroke properties, fill-rule etc. as required by
the resource mode. They only deviate in which set{Stroke,Fill}* variant
they end up calling.
Move the part that updates non-(direct-)paint-server state to a new
helper SVGRenderSupport::updateGraphicsContext, and then sink that out
of the various applyResource methods.
The special case handling of clipping masks in
RenderSVGResourceSolidColor is transformed into a single block, leaving
the generic path oblivious to this detail.

BUG=420022

Review URL: https://codereview.chromium.org/630903003

git-svn-id: svn://svn.chromium.org/blink/trunk@183332 bbb929c8-8fbe-4397-9dbb-9b2b20218538