update travis
diff --git a/.travis.yml b/.travis.yml
index 35e0ab9..0dfdf99 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,8 +3,15 @@
 dart:
   - dev
 
-#before_install:
-#  - export DISPLAY=:99.0
-#  - sh -e /etc/init.d/xvfb start
+addons:
+  chrome: stable
+
+services:
+  - xvfb
 
 script: ./tool/travis.sh
+
+# Only building master means that we don't run two builds for each pull request.
+branches:
+  only:
+    - master