Update dwds changelog and version (#1516)

diff --git a/dwds/CHANGELOG.md b/dwds/CHANGELOG.md
index 3834250..98e3350 100644
--- a/dwds/CHANGELOG.md
+++ b/dwds/CHANGELOG.md
@@ -1,8 +1,15 @@
-## 12.1.1-dev
+## 13.0.0-dev
 - Change wording of paused overlay from "Paused in Dart DevTools" to "Paused"
 - Allow sending back the Dart DevTools URL from DWDS instead of launching 
   Dart DevTools, to support embedding Dart DevTools in Chrome DevTools.
 - Temporarily disable the paused in debugger overlay.
+- Add `SdkConfiguration` and `SdkConfigurationProvider` classes to allow
+  for lazily created SDK configurations.
+
+**Breaking changes:**
+- `Dwds.start` and `ExpressionCompilerService` now take 
+  `sdkConfigurationProvider` argument instead of separate SDK-related file 
+  paths.
 
 ## 12.1.0
 - Update _fe_analyzer_shared to version ^34.0.0.
diff --git a/dwds/lib/src/version.dart b/dwds/lib/src/version.dart
index 20f8ac3..455ea9c 100644
--- a/dwds/lib/src/version.dart
+++ b/dwds/lib/src/version.dart
@@ -1,2 +1,2 @@
 // Generated code. Do not modify.
-const packageVersion = '12.1.1-dev';
+const packageVersion = '13.0.0-dev';
diff --git a/dwds/pubspec.yaml b/dwds/pubspec.yaml
index b6308d5..de9ad15 100644
--- a/dwds/pubspec.yaml
+++ b/dwds/pubspec.yaml
@@ -1,6 +1,6 @@
 name: dwds
 # Every time this changes you need to run `dart run build_runner build`.
-version: 12.1.1-dev
+version: 13.0.0-dev
 homepage: https://github.com/dart-lang/webdev/tree/master/dwds
 description: >-
   A service that proxies between the Chrome debug protocol and the Dart VM