- Use named constant kNullable instead of true.

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, 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_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 284 matching lines @@
   static CompileType FromAbstractType(const AbstractType& type,
                                        bool is_nullable = kNullable);
 
   // Create a new CompileType representing an value with the given class id.
   // Resulting CompileType is nullable only if cid is kDynamicCid or kNullCid.
   static CompileType FromCid(intptr_t cid);
 
   // Create None CompileType. It is the bottom of the lattice and is used to
   // represent type of the phi that was not yet inferred.
   static CompileType None() {
-    return CompileType(true, kIllegalCid, NULL);
+    return CompileType(kNullable, kIllegalCid, NULL);
   }
 
   // Create Dynamic CompileType. It is the top of the lattice and is used to
   // represent unknown type.
   static CompileType Dynamic();
 
   static CompileType Null();
 
   // Create non-nullable Bool type.
   static CompileType Bool();
@@ skipping 6737 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_