Only display 'nits' in verbose mode.

pkg/front_end/lib/src/fasta/messages.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library fasta.messages;
 
 import 'package:kernel/ast.dart' show Location, Program;
 
 import 'util/relativize.dart' show relativizeUri;
 
 import 'compiler_context.dart' show CompilerContext;
 
 import 'errors.dart' show InputError;
 
 import 'colors.dart' show cyan, magenta;
 
-const bool hideNits = false;
-
 const bool hideWarnings = false;
 
 bool get errorsAreFatal => CompilerContext.current.options.errorsAreFatal;
 
 bool get nitsAreFatal => CompilerContext.current.options.nitsAreFatal;
 
 bool get warningsAreFatal => CompilerContext.current.options.warningsAreFatal;
 
 bool get isVerbose => CompilerContext.current.options.verbose;
 
+bool get hideNits => !isVerbose;
+
 void warning(Uri uri, int charOffset, String message) {
   if (hideWarnings) return;
   print(format(uri, charOffset, colorWarning("Warning: $message")));
   if (warningsAreFatal) {
     if (isVerbose) print(StackTrace.current);
     throw new InputError(
         uri, charOffset, "Compilation aborted due to fatal warnings.");
   }
 }
 
@@ skipping 30 matching lines @@
   }
 }
 
 Location getLocation(String path, int charOffset) {
   if (CompilerContext.current.uriToSource[path] == null) {
     return new Location(path, 1, 1);
   }
   return new Program(null, CompilerContext.current.uriToSource)
       .getLocation(path, charOffset);
 }