Remove unused Zone argument from InitializeAstVisitor

src/ast-expression-visitor.cc

 // Copyright 2015 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.
 
 #include "src/v8.h"
 
 #include "src/ast-expression-visitor.h"
 
 #include "src/ast.h"
 #include "src/codegen.h"
@@ skipping 14 matching lines @@
 #define RECURSE_EXPRESSION(call)    \
   do {                              \
     DCHECK(!HasStackOverflow());    \
     ++depth_;                       \
     call;                           \
     --depth_;                       \
     if (HasStackOverflow()) return; \
   } while (false)
 
 
-AstExpressionVisitor::AstExpressionVisitor(Isolate* isolate, Zone* zone,
+AstExpressionVisitor::AstExpressionVisitor(Isolate* isolate,
                                            FunctionLiteral* root)
     : root_(root), depth_(0) {
-  InitializeAstVisitor(isolate, zone);
+  InitializeAstVisitor(isolate);
 }
 
 
 void AstExpressionVisitor::Run() { RECURSE(VisitFunctionLiteral(root_)); }
 
 
 void AstExpressionVisitor::VisitVariableDeclaration(VariableDeclaration* decl) {
 }
 
 
@@ skipping 298 matching lines @@
 
 void AstExpressionVisitor::VisitSuperPropertyReference(
     SuperPropertyReference* expr) {}
 
 
 void AstExpressionVisitor::VisitSuperCallReference(SuperCallReference* expr) {}
 
 
 }  // namespace internal
 }  // namespace v8