Revert "Revert "Change image encode api to return sk_sp""

This reverts commit 64778d9f275d8ce3df8f4ab39ff334b7ef5b70d3.

Bug: skia:
Change-Id: I779515ff1e16a40c33890a4bac7a8a07171aadfe
Reviewed-on: https://skia-review.googlesource.com/22261
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/src/pipe/SkPipeCanvas.cpp b/src/pipe/SkPipeCanvas.cpp
index 7b665d9..226a957 100644
--- a/src/pipe/SkPipeCanvas.cpp
+++ b/src/pipe/SkPipeCanvas.cpp
@@ -828,9 +828,9 @@
 
 static sk_sp<SkData> default_image_serializer(SkImage* image) {
     A8Serializer serial;
-    sk_sp<SkData> data(image->encode(&serial));
+    sk_sp<SkData> data = image->encodeToData(&serial);
     if (!data) {
-        data.reset(image->encode());
+        data = image->encodeToData();
     }
     return data;
 }