Use visitDOMWrapper to preserve WebGL JS object wrappers

third_party/WebKit/Source/bindings/modules/v8/custom/V8WebGLRenderingContextCustom.cpp

Index: third_party/WebKit/Source/bindings/modules/v8/custom/V8WebGLRenderingContextCustom.cpp
diff --git a/third_party/WebKit/Source/bindings/modules/v8/custom/V8WebGLRenderingContextCustom.cpp b/third_party/WebKit/Source/bindings/modules/v8/custom/V8WebGLRenderingContextCustom.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..09ca973c032ba17c9a60849ad8ecca3a2cadeb90
--- /dev/null
+++ b/third_party/WebKit/Source/bindings/modules/v8/custom/V8WebGLRenderingContextCustom.cpp
@@ -0,0 +1,19 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "bindings/modules/v8/V8WebGLRenderingContext.h"
+
+#include "modules/webgl/WebGLRenderingContextBase.h"
+
+using namespace WTF;
+
+namespace blink {
+
+void V8WebGLRenderingContext::visitDOMWrapperCustom(v8::Isolate* isolate, ScriptWrappable* scriptWrappable, const v8::Persistent<v8::Object>& wrapper)
+{
+    WebGLRenderingContext* impl = scriptWrappable->toImpl<WebGLRenderingContext>();
+    impl->visitChildDOMWrappers(isolate, wrapper);
+}
+
+} // namespace blink