bindings: Supports constructor attributes on prototype chains.

Source/bindings/core/v8/V8Binding.cpp

Index: Source/bindings/core/v8/V8Binding.cpp
diff --git a/Source/bindings/core/v8/V8Binding.cpp b/Source/bindings/core/v8/V8Binding.cpp
index b010879387e759cdfb0c3588e03603a0eaeb03f1..956026bf0e9d01f35f727a489aac371f031ce90d 100644
--- a/Source/bindings/core/v8/V8Binding.cpp
+++ b/Source/bindings/core/v8/V8Binding.cpp
@@ -74,6 +74,21 @@
 
 namespace blink {
 
+namespace {
+
+template<class Callback>
+void v8ConstructorAttributeGetter(const Callback& info)
+{
+    v8::Local<v8::Value> data = info.Data();
+    ASSERT(data->IsExternal());
+    V8PerContextData* perContextData = V8PerContextData::from(info.Holder()->CreationContext());
+    if (!perContextData)
+        return;
+    v8SetReturnValue(info, perContextData->constructorForType(WrapperTypeInfo::unwrap(data)));
+}
+
+} // namespace
+
 void setArityTypeError(ExceptionState& exceptionState, const char* valid, unsigned provided)
 {
     exceptionState.throwTypeError(ExceptionMessages::invalidArity(valid, provided));
@@ -1045,4 +1060,14 @@ PassRefPtr<TraceEvent::ConvertableToTraceFormat> devToolsTraceEventData(v8::Isol
     return InspectorFunctionCallEvent::data(context, info.scriptId(), info.resourceName(), info.lineNumber());
 }
 
+void v8ConstructorAttributeGetterAsProperty(v8::Local<v8::String> propertyName, const v8::PropertyCallbackInfo<v8::Value>& info)
+{
+    v8ConstructorAttributeGetter(info);
+}
+
+void v8ConstructorAttributeGetterAsAccessor(const v8::FunctionCallbackInfo<v8::Value>& info)
+{
+    v8ConstructorAttributeGetter(info);
+}
+
 } // namespace blink