add backdrop option to SaveLayerRec

src/core/SkRecorder.cpp

Index: src/core/SkRecorder.cpp
diff --git a/src/core/SkRecorder.cpp b/src/core/SkRecorder.cpp
index 67429a691edea364d9073ecd805f4a5a60823e16..01c28dfc2b49ebcf8bedd8e1069c224c9dda1d74 100644
--- a/src/core/SkRecorder.cpp
+++ b/src/core/SkRecorder.cpp
@@ -337,7 +337,8 @@ void SkRecorder::willSave() {
 }
 
 SkCanvas::SaveLayerStrategy SkRecorder::getSaveLayerStrategy(const SaveLayerRec& rec) {
-    APPEND(SaveLayer, this->copy(rec.fBounds), this->copy(rec.fPaint), rec.fSaveLayerFlags);
+    APPEND(SaveLayer,
+           this->copy(rec.fBounds), this->copy(rec.fPaint), rec.fBackdrop, rec.fSaveLayerFlags);
     return SkCanvas::kNoLayer_SaveLayerStrategy;
 }