Expose v8 context a MessagePort lives in to give content side code a valid context to (de)serialize…

Source/core/dom/MessagePort.cpp

Index: Source/core/dom/MessagePort.cpp
diff --git a/Source/core/dom/MessagePort.cpp b/Source/core/dom/MessagePort.cpp
index 46b53945e60a5e66b66a90cbbb99b8b99db19088..da4fa3b35c033a8a2c8b70e001f8f96f521e732d 100644
--- a/Source/core/dom/MessagePort.cpp
+++ b/Source/core/dom/MessagePort.cpp
@@ -61,6 +61,8 @@ MessagePort::MessagePort(ExecutionContext& executionContext)
 MessagePort::~MessagePort()
 {
     close();
+    if (m_scriptStateForConversion)
+        m_scriptStateForConversion->disposePerContextData();
 }
 
 void MessagePort::postMessage(ExecutionContext*, PassRefPtr<SerializedScriptValue> message, const MessagePortArray* ports, ExceptionState& exceptionState)
@@ -266,4 +268,20 @@ DEFINE_TRACE(MessagePort)
     EventTargetWithInlineData::trace(visitor);
 }
 
+v8::Isolate* MessagePort::scriptIsolate()
+{
+    ASSERT(executionContext());
+    return toIsolate(executionContext());
+}
+
+v8::Local<v8::Context> MessagePort::scriptContextForMessageConversion()
+{
+    ASSERT(executionContext());
+    if (!m_scriptStateForConversion) {
+        v8::Isolate* isolate = scriptIsolate();
+        m_scriptStateForConversion = ScriptState::create(v8::Context::New(isolate), DOMWrapperWorld::create(isolate));
+    }
+    return m_scriptStateForConversion->context();
+}
+
 } // namespace blink