Support luminance-alpha GL format for YUVA planes

Bug: skia:10632
Change-Id: Ic91510b55644c15ee4eb5f96e7c35193b5ce49df
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/344761
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
diff --git a/RELEASE_NOTES.txt b/RELEASE_NOTES.txt
index 96e2c31..6021ad4 100644
--- a/RELEASE_NOTES.txt
+++ b/RELEASE_NOTES.txt
@@ -10,6 +10,10 @@
     a vector pointing towards the light, and light radius is blur radius at elevation 1.
     https://review.skia.org/321792
 
+  * Support GL_LUMINANCE8_ALPHA8 textures. These can be used with GrBackendTexture APIs
+    on GrDirectContext and as planes of YUVA images via GrYUVABackendTextures.
+    https://review.skia.org/344761
+
   * Removed previously deprecated SkImage::MakeFromYUVATexturesCopyToExternal.
     https://review.skia.org/342077