Temporarily uncomment logEvent to make build bot green.

pkg/front_end/lib/src/fasta/parser/listener.dart

Index: pkg/front_end/lib/src/fasta/parser/listener.dart
diff --git a/pkg/front_end/lib/src/fasta/parser/listener.dart b/pkg/front_end/lib/src/fasta/parser/listener.dart
index 47cb4ff3e848f33bd8bee01a9846d7e7b76c0545..907571041e5d63ddc1e233a10000ea0949f9cb4e 100644
--- a/pkg/front_end/lib/src/fasta/parser/listener.dart
+++ b/pkg/front_end/lib/src/fasta/parser/listener.dart
@@ -68,7 +68,7 @@ class Listener {
   void beginCaseExpression(Token caseKeyword) {}
 
   void endCaseExpression(Token colon) {
-    logEvent("CaseExpression");
+    // logEvent("CaseExpression");
   }
 
   void beginClassBody(Token token) {}