SkColorSetA now warns if the result is unused.

Change-Id: Ie0d2ec6e1ca1ddeb83338df232570443502e6cdb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/268697
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
diff --git a/RELEASE_NOTES.txt b/RELEASE_NOTES.txt
index f10c3f1..8bfd999 100644
--- a/RELEASE_NOTES.txt
+++ b/RELEASE_NOTES.txt
@@ -7,6 +7,8 @@
 Milestone 82
 
 <Insert new notes here- top is most recent.>
+  * SkColorSetA now warns if the result is unused.
+
   * An SkImageInfo with a null SkColorSpace passed to SkCodec::getPixels() and
     related calls is treated as a request to do no color correction at decode
     time.