One Zone per CompilationInfo.

src/zone-inl.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 22 matching lines @@
 #include "counters.h"
 #include "isolate.h"
 #include "utils.h"
 #include "v8-counters.h"
 
 namespace v8 {
 namespace internal {
 
 
 inline void* Zone::New(int size) {
-  ASSERT(ZoneScope::nesting() > 0);
+  ASSERT(scope_nesting_ > 0);
   // Round up the requested size to fit the alignment.
   size = RoundUp(size, kAlignment);
 
   // If the allocation size is divisible by 8 then we return an 8-byte aligned
   // address.
   if (kPointerSize == 4 && kAlignment == 4) {
     position_ += ((~size) & 4) & (reinterpret_cast<intptr_t>(position_) & 4);
   } else {
     ASSERT(kAlignment >= kPointerSize);
   }
@@ skipping 49 matching lines @@
   return zone_->New(size);
 }
 
 
 template <typename T>
 void* ZoneList<T>::operator new(size_t size, Zone* zone) {
   return zone->New(static_cast<int>(size));
 }
 
 
-ZoneScope::ZoneScope(Isolate* isolate, ZoneScopeMode mode)
-    : isolate_(isolate), mode_(mode) {
-  isolate_->zone()->scope_nesting_++;
+ZoneScope::ZoneScope(Zone* zone, ZoneScopeMode mode)
+    : zone_(zone), mode_(mode) {
+  zone_->scope_nesting_++;
 }
 
 
 bool ZoneScope::ShouldDeleteOnExit() {
-  return isolate_->zone()->scope_nesting_ == 1 && mode_ == DELETE_ON_EXIT;
+  return zone_->scope_nesting_ == 1 && mode_ == DELETE_ON_EXIT;
 }
 
 
-int ZoneScope::nesting() {
-  return Isolate::Current()->zone()->scope_nesting_;
-}
-
-
 } }  // namespace v8::internal
 
 #endif  // V8_ZONE_INL_H_