Add more chrom(e|ium) downloads to .gitignore

Change-Id: Ie16ab8aa22348edb81df438c17b448d3b1f52f60
diff --git a/.gitignore b/.gitignore
index e439c6b..8adb0bf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -122,3 +122,8 @@
 # Backup files
 *.bak
 *.backup
+
+# Chrome
+chrome-headless-shell/
+chrome/
+chromium/