Add optional message to assert in Dart2js.

pkg/compiler/lib/src/resolution/tree_elements.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 dart2js.resolution.tree_elements;
 
 import '../constants/expressions.dart';
 import '../dart_types.dart';
 import '../diagnostics/invariant.dart' show
     invariant;
@@ skipping 53 matching lines @@
   Selector getMoveNextSelector(ForIn node);
   Selector getCurrentSelector(ForIn node);
   TypeMask getIteratorTypeMask(ForIn node);
   TypeMask getMoveNextTypeMask(ForIn node);
   TypeMask getCurrentTypeMask(ForIn node);
   void setIteratorTypeMask(ForIn node, TypeMask mask);
   void setMoveNextTypeMask(ForIn node, TypeMask mask);
   void setCurrentTypeMask(ForIn node, TypeMask mask);
   void setConstant(Node node, ConstantExpression constant);
   ConstantExpression getConstant(Node node);
-  bool isAssert(Send send);
 
   /// Returns the [FunctionElement] defined by [node].
   FunctionElement getFunctionDefinition(FunctionExpression node);
 
   /// Returns target constructor for the redirecting factory body [node].
   ConstructorElement getRedirectingTargetConstructor(
       RedirectingFactoryBody node);
 
   /**
    * Returns [:true:] if [node] is a type literal.
@@ skipping 48 matching lines @@
   Map<Spannable, TypeMask> _typeMasks;
   Map<Node, DartType> _types;
   Setlet<Node> _superUses;
   Setlet<Element> _otherDependencies;
   Map<Node, ConstantExpression> _constants;
   Map<VariableElement, List<Node>> _potentiallyMutated;
   Map<Node, Map<VariableElement, List<Node>>> _potentiallyMutatedIn;
   Map<VariableElement, List<Node>> _potentiallyMutatedInClosure;
   Map<Node, Map<VariableElement, List<Node>>> _accessedByClosureIn;
   Setlet<Element> _elements;
-  Setlet<Send> _asserts;
   Maplet<Send, SendStructure> _sendStructureMap;
   Setlet<DartType> _requiredTypes;
   bool containsTryStatement = false;
 
   /// Map from nodes to the targets they define.
   Map<Node, JumpTarget> _definedTargets;
 
   /// Map from goto statements to their targets.
   Map<GotoStatement, JumpTarget> _usedTargets;
 
@@ skipping 251 matching lines @@
   Iterable<Element> get allElements {
     return _elements != null ? _elements : const <Element>[];
   }
 
   void forEachConstantNode(f(Node n, ConstantExpression c)) {
     if (_constants != null) {
       _constants.forEach(f);
     }
   }
 
-  void setAssert(Send node) {
-    if (_asserts == null) {
-      _asserts = new Setlet<Send>();
-    }
-    _asserts.add(node);
-  }
-
-  bool isAssert(Send node) {
-    return _asserts != null && _asserts.contains(node);
-  }
-
   FunctionElement getFunctionDefinition(FunctionExpression node) {
     return this[node];
   }
 
   ConstructorElement getRedirectingTargetConstructor(
       RedirectingFactoryBody node) {
     return this[node];
   }
 
   void defineTarget(Node node, JumpTarget target) {
@@ skipping 114 matching lines @@
   }
 
   void setCurrentTypeMask(ForIn node, TypeMask mask) {
     _setTypeMask(node.inToken, mask);
   }
 
   TypeMask getCurrentTypeMask(ForIn node) {
     return _getTypeMask(node.inToken);
   }
 }