switch surface to sk_sp

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1817383002
CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot,Build-Mac-Clang-x86_64-Release-CMake-Trybot

Review URL: https://codereview.chromium.org/1817383002
diff --git a/src/core/SkPictureRecord.h b/src/core/SkPictureRecord.h
index 089bc81..129f94f 100644
--- a/src/core/SkPictureRecord.h
+++ b/src/core/SkPictureRecord.h
@@ -149,7 +149,7 @@
         SkASSERT(fWriter.bytesWritten() == initialOffset + size);
     }
 
-    SkSurface* onNewSurface(const SkImageInfo&, const SkSurfaceProps&) override;
+    sk_sp<SkSurface> onNewSurface(const SkImageInfo&, const SkSurfaceProps&) override;
     bool onPeekPixels(SkPixmap*) override { return false; }
 
     void willSave() override;