Add size_t length argument to v8::ArrayBuffer::Allocator::Free.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 11fccdf023999ff3c3a8acf425c669be29cae54c..311ad434de8516dff174558f15dfe8ae45ad8179 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -2425,10 +2425,20 @@ class V8EXPORT ArrayBuffer : public Object {
     }
 
     /**
-     * Free the memory pointed to |data|. That memory is guaranteed to be
-     * previously allocated by |Allocate|.
+     * 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) = 0;
+    virtual void Free(void* data, size_t length) {
+      // Override with call to |Free(void*)| for compatibility
+      // with legacy version.
+      Free(data);
+    }
+
+    /**
+     * Deprecated. Never called directly by V8.
+     * For compatibility with legacy version of this interface.
+     */
+    virtual void Free(void* data);
   };
 
   /**