Added zone tracing

src/zone/zone.h

 // Copyright 2012 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_ZONE_ZONE_H_
 #define V8_ZONE_ZONE_H_
 
 #include <limits>
 
 #include "src/base/hashmap.h"
@@ skipping 13 matching lines @@
 // the abstract syntax tree, which is deallocated after compilation.
 //
 // Note: There is no need to initialize the Zone; the first time an
 // allocation is attempted, a segment of memory will be requested
 // through the allocator.
 //
 // Note: The implementation is inherently not thread safe. Do not use
 // from multi-threaded code.
 class V8_EXPORT_PRIVATE Zone final {
  public:
-  explicit Zone(AccountingAllocator* allocator);
+  explicit Zone(AccountingAllocator* allocator, const char* name = "unnamed");
   ~Zone();
 
   // Allocate 'size' bytes of memory in the Zone; expands the Zone by
   // allocating new segments of memory on demand using malloc().
   void* New(size_t size);
 
   template <typename T>
   T* NewArray(size_t length) {
     DCHECK_LT(length, std::numeric_limits<size_t>::max() / sizeof(T));
     return static_cast<T*>(New(length * sizeof(T)));
   }
 
   // Returns true if more memory has been allocated in zones than
   // the limit allows.
   bool excess_allocation() const {
     return segment_bytes_allocated_ > kExcessLimit;
   }
 
+  const char* name() const { return name_; }
+
   size_t allocation_size() const { return allocation_size_; }
 
   AccountingAllocator* allocator() const { return allocator_; }
 
  private:
 // All pointers returned from New() have this alignment.  In addition, if the
 // object being allocated has a size that is divisible by 8 then its alignment
 // will be 8. ASan requires 8-byte alignment.
 #ifdef V8_USE_ADDRESS_SANITIZER
   static const size_t kAlignment = 8;
@@ skipping 34 matching lines @@
 
   // The free region in the current (front) segment is represented as
   // the half-open interval [position, limit). The 'position' variable
   // is guaranteed to be aligned as dictated by kAlignment.
   Address position_;
   Address limit_;
 
   AccountingAllocator* allocator_;
 
   Segment* segment_head_;
+  const char* name_;
 };
 
 // ZoneObject is an abstraction that helps define classes of objects
 // allocated in the Zone. Use it as a base class; see ast.h.
 class ZoneObject {
  public:
   // Allocate a new ZoneObject of 'size' bytes in the Zone.
   void* operator new(size_t size, Zone* zone) { return zone->New(size); }
 
   // Ideally, the delete operator should be private instead of
@@ skipping 96 matching lines @@
 
 typedef base::PointerTemplateHashMapImpl<ZoneAllocationPolicy> ZoneHashMap;
 
 typedef base::CustomMatcherTemplateHashMapImpl<ZoneAllocationPolicy>
     CustomMatcherZoneHashMap;
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ZONE_ZONE_H_