change signature for virtual related to saveLayer, passing SaveLayerRec

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1533953002

NOTREECHECKS=True

Review URL: https://codereview.chromium.org/1533953002
diff --git a/src/core/SkPictureRecord.h b/src/core/SkPictureRecord.h
index 3dcaa6c..2e1e62a 100644
--- a/src/core/SkPictureRecord.h
+++ b/src/core/SkPictureRecord.h
@@ -153,7 +153,7 @@
     bool onPeekPixels(SkPixmap*) override { return false; }
 
     void willSave() override;
-    SaveLayerStrategy willSaveLayer(const SkRect*, const SkPaint*, SaveFlags) override;
+    SaveLayerStrategy getSaveLayerStrategy(const SaveLayerRec&) override;
     void willRestore() override;
 
     void didConcat(const SkMatrix&) override;
@@ -218,7 +218,7 @@
     size_t recordClipPath(int pathID, SkRegion::Op op, bool doAA);
     size_t recordClipRegion(const SkRegion& region, SkRegion::Op op);
     void recordSave();
-    void recordSaveLayer(const SkRect* bounds, const SkPaint* paint, SaveFlags flags);
+    void recordSaveLayer(const SaveLayerRec&);
     void recordRestore(bool fillInSkips = true);
 
 private: