Speed up fix for expando-loss conformance test.

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

Index: third_party/WebKit/Source/modules/webgl/WebGLVertexArrayObjectBase.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLVertexArrayObjectBase.cpp b/third_party/WebKit/Source/modules/webgl/WebGLVertexArrayObjectBase.cpp
index c0c5adaec0da11485acd10929cc24e70de4a0884..7f91e451f67fcef06a07490a3724432359adaebf 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLVertexArrayObjectBase.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGLVertexArrayObjectBase.cpp
@@ -109,6 +109,11 @@ void WebGLVertexArrayObjectBase::unbindBuffer(WebGLBuffer* buffer)
     }
 }
 
+V8CopyablePersistent<v8::Array>* WebGLVertexArrayObjectBase::getPersistentCache()
+{
+    return &m_arrayBufferWrappers;
+}
+
 DEFINE_TRACE(WebGLVertexArrayObjectBase)
 {
     visitor->trace(m_boundElementArrayBuffer);