Version 2.1.0-dev.4.0

Merge commit 'f2e6e7255abf9f85db1b9bf70905b01049747f24' into dev
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 76ca9f1..3b3a06d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,16 +1,4 @@
-## 2.1.0-dev.XX.0
-(Add new changes here, and they will be copied to the change section for the
-  next dev version)
-
-### Language
-
-### Dart VM
-
-### Tool Changes
-
-#### Pub
-
-#### Other Tools
+## 2.1.0-dev.4.0
 
 ### Core library changes
 
@@ -20,6 +8,15 @@
     be unmodifiable incorrectly allowed new methods added in Dart 2 to
     succeed.
 
+## 2.1.0-dev.3.1
+
+### Tool Changes
+
+#### dartanalyzer
+
+* Fix a bug in analyzer by cherry-picking commit
+  bd9645abad40d14c8cd9197dfb5c9cc45b20e9d6
+
 ## 2.1.0-dev.3.0
 
 ### Core library changes
diff --git a/tools/VERSION b/tools/VERSION
index 3408fb4..69aa10a 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -23,9 +23,9 @@
 #  * Making cherry-picks to stable channel
 #     - increase PATCH by 1
 #
-CHANNEL be
+CHANNEL dev
 MAJOR 2
 MINOR 1
 PATCH 0
-PRERELEASE 0
+PRERELEASE 4
 PRERELEASE_PATCH 0