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

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

Index: third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp b/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
index 099ed9080c084be9c1987ce7a1e9d5a4746a0cb6..df578ff15318c34ce81577ef620cf34b3cddc350 100644
--- a/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
@@ -30,6 +30,7 @@
 #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"
@@ -279,6 +280,7 @@ CanvasRenderingContext* HTMLCanvasElement::getCanvasRenderingContext(
   }
   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();
 }