expose direct methods for decoding to an image

These are meant to contrast MakeFromEncoded(), and emphasize that it is deferred/cached,
while the new methods are not.

Change-Id: I83ac22394cb14cdc84ff8507a514bf708734b84f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/234476
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/src/image/SkImage.cpp b/src/image/SkImage.cpp
index 079992a..ae0998c 100644
--- a/src/image/SkImage.cpp
+++ b/src/image/SkImage.cpp
@@ -410,6 +410,10 @@
 
 #if !SK_SUPPORT_GPU
 
+sk_sp<SkImage> SkImage::DecodeToTexture(GrContext*, const void*, size_t, const SkIRect*) {
+    return nullptr;
+}
+
 sk_sp<SkImage> SkImage::MakeFromTexture(GrContext* ctx,
                                         const GrBackendTexture& tex, GrSurfaceOrigin origin,
                                         SkColorType ct, SkAlphaType at, sk_sp<SkColorSpace> cs,