Make cc/paint have concrete types

printing/pdf_metafile_skia.cc

Index: printing/pdf_metafile_skia.cc
diff --git a/printing/pdf_metafile_skia.cc b/printing/pdf_metafile_skia.cc
index 6b548afd76b08c940044eb5ab37e40b40b13dada..3261430205f72629bda8145fba1a403f25756dca 100644
--- a/printing/pdf_metafile_skia.cc
+++ b/printing/pdf_metafile_skia.cc
@@ -200,9 +200,9 @@ bool PdfMetafileSkia::FinishDocument() {
   }
 
   for (const Page& page : data_->pages_) {
-    cc::PaintCanvas* canvas(
+    cc::PaintCanvas canvas(
         doc->beginPage(page.size_.width(), page.size_.height()));
-    canvas->drawPicture(page.content_);
+    page.content_->playback(&canvas);
     doc->endPage();
   }
   doc->close();