Remove CrossThreadPersistent::release

third_party/WebKit/Source/platform/heap/Persistent.h

 // Copyright 2016 The Chromium 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 Persistent_h
 #define Persistent_h
 
 #include "platform/heap/Heap.h"
 #include "platform/heap/Member.h"
 #include "platform/heap/PersistentNode.h"
@@ skipping 436 matching lines @@
   CrossThreadPersistent(const CrossThreadPersistent& other) : Parent(other) {}
   template <typename U>
   CrossThreadPersistent(const CrossThreadPersistent<U>& other)
       : Parent(other) {}
   template <typename U>
   CrossThreadPersistent(const Member<U>& other) : Parent(other) {}
   CrossThreadPersistent(WTF::HashTableDeletedValueType x) : Parent(x) {}
 
   T* atomicGet() { return Parent::atomicGet(); }
 
+  // Instead of using release(), assign then clear() instead.
+  // Using release() with per thread heap enabled can cause the object to be
+  // destroyed before assigning it to a new handle.
+  T* release() = delete;
+
   template <typename U>
   CrossThreadPersistent& operator=(U* other) {
     Parent::operator=(other);
     return *this;
   }
 
   CrossThreadPersistent& operator=(std::nullptr_t) {
     Parent::operator=(nullptr);
     return *this;
   }
@@ skipping 336 matching lines @@
   static blink::CrossThreadPersistent<T> Unwrap(
       const blink::CrossThreadWeakPersistent<T>& wrapped) {
     blink::CrossThreadPersistentRegion::LockScope persistentLock(
         blink::ProcessHeap::crossThreadPersistentRegion());
     return blink::CrossThreadPersistent<T>(wrapped.get());
   }
 };
 }
 
 #endif  // Persistent_h