Fixes for exit problems.

pkg/analyzer/lib/src/services/runtime/coverage/coverage_impl.dart

Index: pkg/analyzer/lib/src/services/runtime/coverage/coverage_impl.dart
diff --git a/pkg/analyzer/lib/src/services/runtime/coverage/coverage_impl.dart b/pkg/analyzer/lib/src/services/runtime/coverage/coverage_impl.dart
index bc1568a4271a1a008a5a84e175c238fa8b52232f..bf245d5d222137541151c3648ffccaa2d2616dd8 100644
--- a/pkg/analyzer/lib/src/services/runtime/coverage/coverage_impl.dart
+++ b/pkg/analyzer/lib/src/services/runtime/coverage/coverage_impl.dart
@@ -119,7 +119,7 @@ abstract class RewriteServer {
   }
 
   Future sendFile(HttpRequest request, File file) {
-    file.resolveSymbolicLinks().then((fullPath) {
+    return file.resolveSymbolicLinks().then((fullPath) {
       return file.openRead().pipe(request.response);
     });
   }