Use visitDOMWrapper to preserve WebGL JS object wrappers

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

Index: third_party/WebKit/Source/modules/webgl/WebGLObject.h
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLObject.h b/third_party/WebKit/Source/modules/webgl/WebGLObject.h
index 6fe0442298e365e767876869325286932dc2abce..50aad57ab19205c8edcb3199eb49434e20ab56ba 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLObject.h
+++ b/third_party/WebKit/Source/modules/webgl/WebGLObject.h
@@ -26,6 +26,7 @@
 #ifndef WebGLObject_h
 #define WebGLObject_h
 
+#include "bindings/core/v8/DOMWrapperWorld.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "platform/heap/Handle.h"
 #include "third_party/khronos/GLES2/gl2.h"
@@ -77,9 +78,20 @@ public:
     virtual bool validate(const WebGLContextGroup*, const WebGLRenderingContextBase*) const = 0;
     virtual bool hasObject() const = 0;
 
+    static void trySetWrapperReferencesInAllWorlds(const v8::Persistent<v8::Object>& wrapper, ScriptWrappable* scriptWrappable, v8::Isolate* isolate)
+    {
+        if (scriptWrappable) {

[haraken, 2016/08/31 23:14:50]

I'd prefer moving the null check to DOMWrapperWorld.

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

Done.

+            DOMWrapperWorld::setWrapperReferencesInAllWorlds(wrapper, scriptWrappable, isolate);
+        }
+    }
+
     DEFINE_INLINE_VIRTUAL_TRACE() { }
 
 protected:
+    // To allow WebGL[2]RenderingContextBase to call visitChildDOMWrappers.
+    friend class WebGLRenderingContextBase;
+    friend class WebGL2RenderingContextBase;
+
     explicit WebGLObject(WebGLRenderingContextBase*);
 
     // deleteObjectImpl should be only called once to delete the OpenGL resource.
@@ -93,6 +105,8 @@ protected:
 
     virtual gpu::gles2::GLES2Interface* getAGLInterface() const = 0;
 
+    virtual void visitChildDOMWrappers(v8::Isolate*, const v8::Persistent<v8::Object>&) { }
+
 private:
     unsigned m_attachmentCount;
     bool m_deleted;