One Zone per CompilationInfo.

src/ast.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2621 matching lines @@
 };
 
 
 
 // ----------------------------------------------------------------------------
 // AstNode factory
 
 template<class Visitor>
 class AstNodeFactory BASE_EMBEDDED {
  public:
-  explicit AstNodeFactory(Isolate* isolate)
+  AstNodeFactory(Isolate* isolate, Zone* zone)
       : isolate_(isolate),
-        zone_(isolate_->zone()) { }
+        zone_(zone) { }
 
   Visitor* visitor() { return &visitor_; }
 
 #define VISIT_AND_RETURN(NodeType, node) \
   visitor_.Visit##NodeType((node)); \
   return node;
 
   VariableDeclaration* NewVariableDeclaration(VariableProxy* proxy,
                                               VariableMode mode,
                                               Scope* scope) {
@@ skipping 49 matching lines @@
     VISIT_AND_RETURN(ModulePath, module)
   }
 
   ModuleUrl* NewModuleUrl(Handle<String> url) {
     ModuleUrl* module = new(zone_) ModuleUrl(url, zone_);
     VISIT_AND_RETURN(ModuleUrl, module)
   }
 
   Block* NewBlock(ZoneStringList* labels,
                   int capacity,
-                  bool is_initializer_block,
-                  Zone* zone) {
+                  bool is_initializer_block) {
     Block* block = new(zone_) Block(
-        isolate_, labels, capacity, is_initializer_block, zone);
+        isolate_, labels, capacity, is_initializer_block, zone_);
     VISIT_AND_RETURN(Block, block)
   }
 
 #define STATEMENT_WITH_LABELS(NodeType) \
   NodeType* New##NodeType(ZoneStringList* labels) { \
     NodeType* stmt = new(zone_) NodeType(isolate_, labels); \
     VISIT_AND_RETURN(NodeType, stmt); \
   }
   STATEMENT_WITH_LABELS(DoWhileStatement)
   STATEMENT_WITH_LABELS(WhileStatement)
@@ skipping 257 matching lines @@
  private:
   Isolate* isolate_;
   Zone* zone_;
   Visitor visitor_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_