SkDynamicMemoryWStream::detachAsStream() returns unique_ptr

https://crrev.com/2747183002 must land first.
Change-Id: I65d1285a24d63c2c2f18662d511dea1c399511e1
Reviewed-on: https://skia-review.googlesource.com/9682
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
diff --git a/dm/DM.cpp b/dm/DM.cpp
index cc662bc..4b51030 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -1089,7 +1089,7 @@
             }
 
             // We're likely switching threads here, so we must capture by value, [=] or [foo,bar].
-            SkStreamAsset* data = stream.detachAsStream();
+            SkStreamAsset* data = stream.detachAsStream().release();
             gDefinitelyThreadSafeWork.add([task,name,bitmap,data]{
                 std::unique_ptr<SkStreamAsset> ownedData(data);