[release] Add release notes for 2.9.3

https://github.com/dart-lang/sdk/issues/43287

Change-Id: I2880455fdd0ec94d1fa6e037cf408f4ca3f05e65
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/161943
Reviewed-by: Michael Thomsen <mit@google.com>
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 011e3ca..9b56ce5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -75,6 +75,13 @@
 * Fix: Avoid exponential behaviour of error reporting from the solver.
 * Fix: Refresh binstubs after recompile in global run.
 
+## 2.9.3 - 2020-09-08
+
+This is a patch release that fixes DDC to handle a breaking change in Chrome
+(issue [#43193][]).
+
+[#43193]: https://github.com/dart-lang/sdk/issues/43193
+
 ## 2.9.2 - 2020-08-26
 
 This is a patch release that fixes transient StackOverflow exceptions when