Update min SDK version to `2.15.0` (#1463)

diff --git a/dwds/CHANGELOG.md b/dwds/CHANGELOG.md
index 50e586e..579144f 100644
--- a/dwds/CHANGELOG.md
+++ b/dwds/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 11.5.1
+
+- Update SDK contraint to `>=2.15.0 <3.0.0`.
+
 ## 11.5.0
 
 - Support hot restart in a multi-app scenario with legacy modules.
diff --git a/dwds/lib/src/injected/client.js b/dwds/lib/src/injected/client.js
index 80cd7ea..acd5bf5 100644
--- a/dwds/lib/src/injected/client.js
+++ b/dwds/lib/src/injected/client.js
@@ -1,4 +1,4 @@
-// Generated by dart2js (NullSafetyMode.unsound, no-legacy-javascript, new-holders, csp), the Dart to JavaScript compiler version: 2.16.0-55.0.dev.
+// Generated by dart2js (NullSafetyMode.unsound, no-legacy-javascript, new-holders, csp), the Dart to JavaScript compiler version: 2.16.0-80.0.dev.
 // The code supports the following hooks:
 // dartPrint(message):
 //    if this function is defined it is called instead of the Dart [print]
diff --git a/dwds/lib/src/version.dart b/dwds/lib/src/version.dart
index 42ce62c..83ab082 100644
--- a/dwds/lib/src/version.dart
+++ b/dwds/lib/src/version.dart
@@ -1,2 +1,2 @@
 // Generated code. Do not modify.
-const packageVersion = '11.5.0';
+const packageVersion = '11.5.1';
diff --git a/dwds/pubspec.yaml b/dwds/pubspec.yaml
index 2ad6e49..c551bc5 100644
--- a/dwds/pubspec.yaml
+++ b/dwds/pubspec.yaml
@@ -1,13 +1,13 @@
 name: dwds
-# Every time this changes you need to run `pub run build_runner build`.
-version: 11.5.0
+# Every time this changes you need to run `dart run build_runner build`.
+version: 11.5.1
 homepage: https://github.com/dart-lang/webdev/tree/master/dwds
 description: >-
   A service that proxies between the Chrome debug protocol and the Dart VM
   service protocol.
 
 environment:
-  sdk: ">=2.14.0 <3.0.0"
+  sdk: ">=2.15.0 <3.0.0"
 
 dependencies:
   async: ^2.3.0
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index f088e21..91b923e 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -4,7 +4,7 @@
 publish_to: none
 
 environment:
-  sdk: ">=2.14.0 <3.0.0"
+  sdk: ">=2.15.0 <3.0.0"
 
 dev_dependencies:
   build_runner: ^2.0.0
diff --git a/fixtures/_webdevSmoke/pubspec.yaml b/fixtures/_webdevSmoke/pubspec.yaml
index 3942994..c15b331 100644
--- a/fixtures/_webdevSmoke/pubspec.yaml
+++ b/fixtures/_webdevSmoke/pubspec.yaml
@@ -7,7 +7,7 @@
 # and build_web_compilers constraint should match those defined
 # in pubspec.dart.
 environment:
-  sdk: '>=2.14.0 <3.0.0'
+  sdk: '>=2.15.0 <3.0.0'
 
 dev_dependencies:
   build_runner: '>=1.6.2 <3.0.0'
diff --git a/fixtures/_webdevSoundSmoke/pubspec.yaml b/fixtures/_webdevSoundSmoke/pubspec.yaml
index 5d2e24f..11aa233 100644
--- a/fixtures/_webdevSoundSmoke/pubspec.yaml
+++ b/fixtures/_webdevSoundSmoke/pubspec.yaml
@@ -2,7 +2,7 @@
 description: A test fixture for webdev testing with sound support.
 
 environment:
-  sdk: '>=2.14.0 <3.0.0'
+  sdk: '>=2.15.0 <3.0.0'
 
 dev_dependencies:
   build_runner: '>=1.6.2 <3.0.0'
diff --git a/frontend_server_common/pubspec.yaml b/frontend_server_common/pubspec.yaml
index ae5ba88..cb5f2bc 100644
--- a/frontend_server_common/pubspec.yaml
+++ b/frontend_server_common/pubspec.yaml
@@ -3,7 +3,7 @@
 description: >-
   Frontend server integration code to use for dwds tests. Mimicks flutter code.
 environment:
-  sdk: ">=2.14.0 <3.0.0"
+  sdk: ">=2.15.0 <3.0.0"
 
 dependencies:
   dwds:
diff --git a/webdev/pubspec.yaml b/webdev/pubspec.yaml
index 9fec3f2..c80632e 100644
--- a/webdev/pubspec.yaml
+++ b/webdev/pubspec.yaml
@@ -1,5 +1,5 @@
 name: webdev
-# Every time this changes you need to run `pub run build_runner build`.
+# Every time this changes you need to run `dart run build_runner build`.
 version: 2.7.7-dev
 # We should not depend on a dev SDK before publishing.
 # publish_to: none
@@ -9,7 +9,7 @@
   features for users and tools to build and deploy web applications with Dart.
 
 environment:
-  sdk: ">=2.14.0 <3.0.0"
+  sdk: ">=2.15.0 <3.0.0"
 
 dependencies:
   args: ^2.0.0