Prepare to introduce RenderSVGContainer for LBSE: move current RenderSVGContainer.(cpp|h) code to LegacyRenderSVGContainer.(cpp|h).
Created attachment 448914 [details] Patch, v1
Committed r287916 (245949@trunk): <https://commits.webkit.org/245949@trunk>
<rdar://problem/87446108>