Remove CrossThreadPersistent::release

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

Index: third_party/WebKit/Source/platform/heap/Persistent.h
diff --git a/third_party/WebKit/Source/platform/heap/Persistent.h b/third_party/WebKit/Source/platform/heap/Persistent.h
index 36539c7efee59f111a0f3b4660e7ed5291eaf188..322054216275a739120a3e58acf2854b919f74f2 100644
--- a/third_party/WebKit/Source/platform/heap/Persistent.h
+++ b/third_party/WebKit/Source/platform/heap/Persistent.h
@@ -454,6 +454,11 @@ class CrossThreadPersistent
 
   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);