Parenthesize expressions as needed in elements text dump.

pkg/analyzer/test/src/summary/resynthesize_common.dart

 // Copyright (c) 2015, 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 test.src.serialization.elements_test;
 
 import 'dart:async';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_resolution_map.dart';
@@ skipping 4627 matching lines @@
 const dynamic vIntLong = 44998905507923676709665;
 const dynamic vDouble = 2.3;
 const dynamic vString = 'abc';
 const dynamic vStringConcat = 'aaabbb';
 const dynamic vStringInterpolation = 'aaa ${true} ${42} bbb';
 const dynamic vSymbol = #aaa.bbb.ccc;
 ''');
     }
   }
 
+  test_const_topLevel_parenthesis() async {

[Brian Wilkerson, 2017/07/19 19:33:15]

Should this also test that unnecessary parentheses are dropped?

+    var library = await checkLibrary(r'''
+const int v1 = (1 + 2) * 3;
+const int v2 = -(1 + 2);
+const int v3 = ('aaa' + 'bbb').length;
+''');
+    checkElementText(library, r'''
+const int v1 = (1 + 2) * 3;
+const int v2 = -(1 + 2);
+const int v3 = ('aaa' + 'bbb').
+        length/*location: dart:core;String;length?*/;
+''');
+  }
+
   test_const_topLevel_prefix() async {
     var library = await checkLibrary(r'''
 const vNotEqual = 1 != 2;
 const vNot = !true;
 const vNegate = -1;
 const vComplement = ~1;
 ''');
     if (isStrongMode) {
       checkElementText(library, r'''
 const bool vNotEqual = 1 != 2;
@@ skipping 8487 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }