[wrapper-tracing] WebGL and friends: Add write barriers

third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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.
@@ skipping 12 matching lines @@
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "core/html/HTMLCanvasElement.h"
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptController.h"
+#include "bindings/core/v8/ScriptWrappableVisitor.h"
 #include "core/HTMLNames.h"
 #include "core/InputTypeNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/TaskRunnerHelper.h"
 #include "core/fileapi/File.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/frame/LocalFrame.h"
@@ skipping 229 matching lines @@
 
   m_context = factory->create(this, attributes, document());
   if (!m_context)
     return nullptr;
 
   if (m_context->is3d()) {
     updateExternallyAllocatedMemory();
   }
   setNeedsCompositingUpdate();
 
+  ScriptWrappableVisitor::writeBarrier(this, m_context);

[Marcel Hlopko, 2016/10/07 12:34:58]

Nit: Can we move write barrier up to line 277?

[Michael Lippautz, 2016/10/07 12:48:52]

Done.

   return m_context.get();
 }
 
 bool HTMLCanvasElement::shouldBeDirectComposited() const {
   return (m_context && m_context->isAccelerated()) ||
          (hasImageBuffer() && buffer()->isExpensiveToPaint()) ||
          (!!m_surfaceLayerBridge);
 }
 
 bool HTMLCanvasElement::isPaintable() const {
@@ skipping 1147 matching lines @@
   mojom::blink::OffscreenCanvasSurfacePtr service;
   Platform::current()->interfaceProvider()->getInterface(
       mojo::GetProxy(&service));
   m_surfaceLayerBridge =
       wrapUnique(new CanvasSurfaceLayerBridge(std::move(service)));
   return m_surfaceLayerBridge->createSurfaceLayer(this->width(),
                                                   this->height());
 }
 
 }  // namespace blink