Fix capturing variables in optimized compilations

runtime/vm/ast.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_AST_H_
 #define VM_AST_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
@@ skipping 522 matching lines @@
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(AssignableNode);
 };
 
 
 class ClosureNode : public AstNode {
  public:
   ClosureNode(TokenPosition token_pos,
               const Function& function,
               AstNode* receiver,  // Non-null for implicit instance closures.
-              LocalScope* scope)  // Null for implicit closures.
+              LocalScope* scope)  // Null for implicit closures or functions
+                                  // that already have a ContextScope because
+                                  // they were compiled before.
       : AstNode(token_pos),
         function_(function),
         receiver_(receiver),
         scope_(scope),
         is_deferred_reference_(false) {
     ASSERT(function_.IsZoneHandle());
-    ASSERT((function_.IsNonImplicitClosureFunction() &&
-            (receiver_ == NULL) && (scope_ != NULL)) ||
+    ASSERT((function_.IsNonImplicitClosureFunction() && (receiver_ == NULL)) ||
            (function_.IsImplicitInstanceClosureFunction() &&
             (receiver_ != NULL) && (scope_ == NULL)) ||
            (function_.IsImplicitStaticClosureFunction() &&
             (receiver_ == NULL) && (scope_ == NULL)));
   }
 
   const Function& function() const { return function_; }
   AstNode* receiver() const { return receiver_; }
   LocalScope* scope() const { return scope_; }
 
@@ skipping 1452 matching lines @@
   const intptr_t try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(InlinedFinallyNode);
 };
 
 }  // namespace dart
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
 #endif  // VM_AST_H_