[release] Merge changelog from dev branch into master

Change-Id: Ib30ca03e2068ebe05a7f00902afcfe62c7ebbc4f
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c593158..931d854 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,27 @@
 ## 2.0.0-dev.48.0
 
+### Language
+
+#### Strong Mode
+
+### Core library changes
+
+### Dart VM
+
+### Tool Changes
+
+#### Pub
+
+#### Other Tools
+
+## 2.0.0-dev.49.0
+
+## 2.0.0-dev.47.0
+
+### Tool Changes
+
+## 2.0.0-dev.48.0
+
 ### Core library changes
 
 * `dart:core`