Fix leaked array buffer allocators of isolates

fxjs/cfxjse_isolatetracker.h

 // Copyright 2016 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef FXJS_CFXJSE_ISOLATETRACKER_H_
 #define FXJS_CFXJSE_ISOLATETRACKER_H_
 
+#include <map>
+#include <memory>
 #include <vector>
 
 #include "v8/include/v8.h"
 
 #include "fxjs/cfxjse_runtimedata.h"
 
 class CFXJSE_ScopeUtil_IsolateHandle {
  public:
   explicit CFXJSE_ScopeUtil_IsolateHandle(v8::Isolate* pIsolate)
       : m_isolate(pIsolate), m_iscope(pIsolate), m_hscope(pIsolate) {}
@@ skipping 30 matching lines @@
   v8::Context::Scope m_cscope;
 };
 
 class CFXJSE_IsolateTracker {
  public:
   typedef void (*DisposeCallback)(v8::Isolate*, bool bOwnedIsolate);
 
   CFXJSE_IsolateTracker();
   ~CFXJSE_IsolateTracker();
 
-  void Append(v8::Isolate* pIsolate);
+  void Append(v8::Isolate* pIsolate,
+              std::unique_ptr<v8::ArrayBuffer::Allocator> alloc);
   void Remove(v8::Isolate* pIsolate, DisposeCallback lpfnDisposeCallback);
   void RemoveAll(DisposeCallback lpfnDisposeCallback);
 
   static CFXJSE_IsolateTracker* g_pInstance;
 
  protected:
   std::vector<v8::Isolate*> m_OwnedIsolates;
+  std::map<v8::Isolate*, std::unique_ptr<v8::ArrayBuffer::Allocator>>
+      m_AllocatorMap;
 };
 
 #endif  // FXJS_CFXJSE_ISOLATETRACKER_H_