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/gm/image_shader.cpp b/gm/image_shader.cpp
index 02e6679..5e55786 100644
--- a/gm/image_shader.cpp
+++ b/gm/image_shader.cpp
@@ -57,7 +57,7 @@
     if (!src) {
         return nullptr;
     }
-    sk_sp<SkData> encoded(src->encode(SkEncodedImageFormat::kPNG, 100));
+    sk_sp<SkData> encoded = src->encodeToData(SkEncodedImageFormat::kPNG, 100);
     if (!encoded) {
         return nullptr;
     }