Speed up fix for expando-loss conformance test.

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

 /*
  * 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 76 matching lines @@
 
     // Wrapper for drawBuffersEXT/drawBuffersARB to work around a driver bug.
     void drawBuffers(const Vector<GLenum>& bufs);
 
     GLenum getDrawBuffer(GLenum);
 
     void readBuffer(const GLenum colorBuffer) { m_readBuffer = colorBuffer; }
 
     GLenum getReadBuffer() const { return m_readBuffer; }
 
+    V8CopyablePersistent<v8::Array>* getPersistentCache();
+
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     explicit WebGLFramebuffer(WebGLRenderingContextBase*);
 
     bool hasObject() const override { return m_object != 0; }
     void deleteObjectImpl(gpu::gles2::GLES2Interface*) override;
 
 private:
     WebGLAttachment* getAttachment(GLenum attachment) const;
@@ skipping 13 matching lines @@
 
     AttachmentMap m_attachments;
     bool m_destructionInProgress;
 
     bool m_hasEverBeenBound;
 
     Vector<GLenum> m_drawBuffers;
     Vector<GLenum> m_filteredDrawBuffers;
 
     GLenum m_readBuffer;
+
+    V8CopyablePersistent<v8::Array> m_attachmentWrappers;
 };
 
 } // namespace blink
 
 #endif // WebGLFramebuffer_h