Provide a convenience array buffer allocator

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 7aad48b4daf2b78f26b8691f55061e478c925f8a..886ab465083e28d71b78b857e87030d5b3d1c779 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -3487,8 +3487,6 @@ class V8_EXPORT ArrayBuffer : public Object {
    *
    * Note that it is unsafe to call back into V8 from any of the allocator
    * functions.
-   *
-   * This API is experimental and may change significantly.
    */
   class V8_EXPORT Allocator { // NOLINT
    public:
@@ -3505,11 +3503,19 @@ class V8_EXPORT ArrayBuffer : public Object {
      * Memory does not have to be initialized.
      */
     virtual void* AllocateUninitialized(size_t length) = 0;
+
     /**
      * Free the memory block of size |length|, pointed to by |data|.
      * That memory is guaranteed to be previously allocated by |Allocate|.
      */
     virtual void Free(void* data, size_t length) = 0;
+
+    /**
+     * malloc/free based convenience allocator.
+     *
+     * Caller takes ownership.
+     */
+    static Allocator* NewDefaultAllocator();
   };
 
   /**