Use visitDOMWrapper to preserve WebGL JS object wrappers

third_party/WebKit/Source/modules/webgl/WebGLFramebuffer.cpp

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 404 matching lines @@
 {
     int index = static_cast<int>(drawBuffer - GL_DRAW_BUFFER0_EXT);
     ASSERT(index >= 0);
     if (index < static_cast<int>(m_drawBuffers.size()))
         return m_drawBuffers[index];
     if (drawBuffer == GL_DRAW_BUFFER0_EXT)
         return GL_COLOR_ATTACHMENT0;
     return GL_NONE;
 }
 
-ScopedPersistent<v8::Array>* WebGLFramebuffer::getPersistentCache()
+void WebGLFramebuffer::visitChildDOMWrappers(v8::Isolate* isolate, const v8::Persistent<v8::Object>& wrapper)
 {
-    return &m_attachmentWrappers;
+    trySetWrapperReferencesInAllWorlds(wrapper, this, isolate);

[Ken Russell (switch to Gerrit), 2016/09/01 21:03:53]

I'd suggest leaving this responsibility to the caller. It seems non-orthogonal
that visitChildDOMWrappers should also mark "this" as being used, rather than
just the objects "this" refers to.

[Kai Ninomiya, 2016/09/02 18:29:22]

Done.

+
+    for (const auto& kv : m_attachments) {
+        trySetWrapperReferencesInAllWorlds(wrapper, kv.value->object(), isolate);
+    }
 }
 
 DEFINE_TRACE(WebGLFramebuffer)
 {
     visitor->trace(m_attachments);
     WebGLContextObject::trace(visitor);
 }
 
 } // namespace blink