Remove GrDirectContext::ComputeImageSize. Use SkImage::textureSize.

Bug: skia:11208
Change-Id: Ie5f56b6d168ab43189be75bb2be60b315e724569
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/371958
Commit-Queue: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
Auto-Submit: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/RELEASE_NOTES.txt b/RELEASE_NOTES.txt
index b845bb1..738f1b3 100644
--- a/RELEASE_NOTES.txt
+++ b/RELEASE_NOTES.txt
@@ -6,8 +6,10 @@
 
 Milestone 90
 ------------
-  * GrDirectContext::ComputeImageSize() no longer takes nextPow2 argument.
+  * GrDirectContext::ComputeImageSize() is removed. Use SkImage::textureSize() instead.
     https://review.skia.org/368621
+    https://review.skia.org/369317
+    https://review.skia.org/371958
 
   * Remove SkImageFilter::MakeMatrixFilter as it was unused and replaced with
     SkImageFilters::MatrixTransform.