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..db87675b99b054252d2685251d01f6becd96f0af 100644
--- a/Source/core/dom/MessagePort.cpp
+++ b/Source/core/dom/MessagePort.cpp
@@ -266,4 +266,20 @@ DEFINE_TRACE(MessagePort)
     EventTargetWithInlineData::trace(visitor);
 }
 
+v8::Isolate* MessagePort::scriptIsolate()
+{
+    ASSERT(executionContext());
+    return toIsolate(executionContext());
+}
+
+v8::Handle<v8::Context> MessagePort::scriptContextForMessageConversion()
+{
+    ASSERT(executionContext());
+    if (!m_scriptStateForConversion) {
+        v8::Isolate* isolate = scriptIsolate();
+        m_scriptStateForConversion = ScriptState::create(v8::Context::New(isolate), DOMWrapperWorld::create(isolate));

[haraken, 2015/02/25 18:40:33]

You need to call:

  m_scriptStateForConversion->disposePerContextData();

in MessagePort's destructor. Otherwise, the context will leak.

[Marijn Kruisselbrink, 2015/02/25 18:45:09]

Done.

+    }
+    return m_scriptStateForConversion->context();
+}
+
 } // namespace blink