Draw recorded content directly into the containing PaintCanvas, when possible.

third_party/WebKit/Source/platform/graphics/paint/PaintArtifact.h

Index: third_party/WebKit/Source/platform/graphics/paint/PaintArtifact.h
diff --git a/third_party/WebKit/Source/platform/graphics/paint/PaintArtifact.h b/third_party/WebKit/Source/platform/graphics/paint/PaintArtifact.h
index 6dc8fd05f11da5a787d0361d2ac035841fb5df8a..b2e7d8514ec0f9eabad5a1c318fe2b47c8c927aa 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/PaintArtifact.h
+++ b/third_party/WebKit/Source/platform/graphics/paint/PaintArtifact.h
@@ -7,6 +7,7 @@
 
 #include "platform/PlatformExport.h"
 #include "platform/graphics/paint/DisplayItemList.h"
+#include "platform/graphics/paint/PaintCanvas.h"
 #include "platform/graphics/paint/PaintChunk.h"
 #include "wtf/Allocator.h"
 #include "wtf/Noncopyable.h"
@@ -73,6 +74,11 @@ class PLATFORM_EXPORT PaintArtifact final {
   // |bounds| is the bounding box of the paint artifact's display list.
   void replay(const FloatRect& bounds, GraphicsContext&) const;
 
+  // Draws the paint artifact to a PaintCanvas.
+  // |bounds| is the bounding box of the paint artifact's display list.
+  // SPv2 only.
+  void replay(const FloatRect& bounds, PaintCanvas&) const;
+
   // Writes the paint artifact into a WebDisplayItemList.
   void appendToWebDisplayItemList(WebDisplayItemList*) const;