Remove unused Zone argument from InitializeAstVisitor

src/typing.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_TYPING_H_
 #define V8_TYPING_H_
 
 #include "src/allocation.h"
 #include "src/ast.h"
 #include "src/effects.h"
@@ skipping 16 matching lines @@
 
  private:
   Effect ObservedOnStack(Object* value);
   void ObserveTypesAtOsrEntry(IterationStatement* stmt);
 
   static const int kNoVar = INT_MIN;
   typedef v8::internal::Effects<int, kNoVar> Effects;
   typedef v8::internal::NestedEffects<int, kNoVar> Store;
 
   Isolate* isolate_;
+  Zone* zone_;
   Handle<JSFunction> closure_;
   Scope* scope_;
   BailoutId osr_ast_id_;
   FunctionLiteral* root_;
   TypeFeedbackOracle oracle_;
   Store store_;
 
+  Zone* zone() const { return zone_; }
   TypeFeedbackOracle* oracle() { return &oracle_; }
 
   void NarrowType(Expression* e, Bounds b) {
     e->set_bounds(Bounds::Both(e->bounds(), b, zone()));
   }
   void NarrowLowerType(Expression* e, Type* t) {
     e->set_bounds(Bounds::NarrowLower(e->bounds(), t, zone()));
   }
 
   Effects EnterEffects() {
@@ skipping 20 matching lines @@
   AST_NODE_LIST(DECLARE_VISIT)
 #undef DECLARE_VISIT
 
   DISALLOW_COPY_AND_ASSIGN(AstTyper);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TYPING_H_