Replace SkAutoTUnref with sk_sp.

Skia would like to remove SkAutoTUnref and replace it with sk_sp.
This also removes the last SkAutoTDelete straggler.

Change-Id: Idd46fcbbffe7fc1edb243b82b1c2f5425ccd60b6
diff --git a/cmds/screencap/screencap.cpp b/cmds/screencap/screencap.cpp
index 7bf073b..a41f122 100644
--- a/cmds/screencap/screencap.cpp
+++ b/cmds/screencap/screencap.cpp
@@ -177,7 +177,7 @@
         if (png) {
             const SkImageInfo info = SkImageInfo::Make(w, h, flinger2skia(f),
                                                        kPremul_SkAlphaType);
-            SkAutoTUnref<SkData> data(SkImageEncoder::EncodeData(info, base, s*bytesPerPixel(f),
+            sk_sp<SkData> data(SkImageEncoder::EncodeData(info, base, s*bytesPerPixel(f),
                     SkImageEncoder::kPNG_Type, SkImageEncoder::kDefaultQuality));
             if (data.get()) {
                 write(fd, data->data(), data->size());