Improve detection of compile-time errors.

utils/kernel-service/kernel-service.dart

Index: utils/kernel-service/kernel-service.dart
diff --git a/utils/kernel-service/kernel-service.dart b/utils/kernel-service/kernel-service.dart
index 335bbbf67c708d2692d978f166c7c00361f8f2b3..a77072d51539a143f9cfa0f0f15c6f801ab96173 100644
--- a/utils/kernel-service/kernel-service.dart
+++ b/utils/kernel-service/kernel-service.dart
@@ -44,7 +44,7 @@ Future<CompilationResult> _processLoadRequestImpl(String inputFilePathOrUri) {
   if (!scriptUri.isScheme('file')) {
     // TODO(vegorov): Reuse loader code to support other schemes.
     return new Future<CompilationResult>.value(new CompilationResult.error(
-        ["Expected 'file' scheme for a script uri: got ${scriptUri.scheme}"]));
+        "Expected 'file' scheme for a script uri: got ${scriptUri.scheme}"));
   }
 
   return parseScript(scriptUri, verbose: verbose);