Revert "Add optional message to assert in Dart2js - continued"

pkg/compiler/lib/src/resolution/tree_elements.dart

Index: pkg/compiler/lib/src/resolution/tree_elements.dart
diff --git a/pkg/compiler/lib/src/resolution/tree_elements.dart b/pkg/compiler/lib/src/resolution/tree_elements.dart
index 120401758a6766c0ddbb052955bc30fdd30dcff6..ce8346ef74e7299c10d0c3066edfd891729feeb2 100644
--- a/pkg/compiler/lib/src/resolution/tree_elements.dart
+++ b/pkg/compiler/lib/src/resolution/tree_elements.dart
@@ -72,6 +72,7 @@ abstract class TreeElements {
   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);
@@ -140,6 +141,7 @@ class TreeElementMapping extends TreeElements {
   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;
@@ -411,6 +413,17 @@ class TreeElementMapping extends TreeElements {
     }
   }
 
+  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];
   }