Remove the dependency of Zone on Isolate

src/compiler/zone-pool.cc

 // Copyright 2014 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/compiler/zone-pool.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
@@ skipping 47 matching lines @@
   // Update max.
   max_allocated_bytes_ = std::max(max_allocated_bytes_, current_total);
   // Drop zone from initial value map.
   InitialValues::iterator it = initial_values_.find(zone);
   if (it != initial_values_.end()) {
     initial_values_.erase(it);
   }
 }
 
 
-ZonePool::ZonePool(Isolate* isolate)
-    : isolate_(isolate), max_allocated_bytes_(0), total_deleted_bytes_(0) {}
+ZonePool::ZonePool() : max_allocated_bytes_(0), total_deleted_bytes_(0) {}
 
 
 ZonePool::~ZonePool() {
   DCHECK(used_.empty());
   DCHECK(stats_.empty());
   for (Zone* zone : unused_) {
     delete zone;
   }
 }
 
@@ skipping 17 matching lines @@
 }
 
 
 Zone* ZonePool::NewEmptyZone() {
   Zone* zone;
   // Grab a zone from pool if possible.
   if (!unused_.empty()) {
     zone = unused_.back();
     unused_.pop_back();
   } else {
-    zone = new Zone(isolate_);
+    zone = new Zone();
   }
   used_.push_back(zone);
   DCHECK_EQ(0, zone->allocation_size());
   return zone;
 }
 
 
 void ZonePool::ReturnZone(Zone* zone) {
   size_t current_total = GetCurrentAllocatedBytes();
   // Update max.
@@ skipping 13 matching lines @@
   } else {
     zone->DeleteAll();
     DCHECK_EQ(0, zone->allocation_size());
     unused_.push_back(zone);
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8