bindings: Use Maybe APIs in ScriptPromise

Source/bindings/core/v8/ScriptValue.h

Index: Source/bindings/core/v8/ScriptValue.h
diff --git a/Source/bindings/core/v8/ScriptValue.h b/Source/bindings/core/v8/ScriptValue.h
index 7ad2aecaed7c51507d12e55ea33d1dd2cecd2704..d234a9783aa9402e8eb8ed1805f85691b89b1571 100644
--- a/Source/bindings/core/v8/ScriptValue.h
+++ b/Source/bindings/core/v8/ScriptValue.h
@@ -67,6 +67,14 @@ public:
         ASSERT(isEmpty() || m_scriptState);
     }
 
+    template <typename T>
+    ScriptValue(ScriptState* scriptState, v8::MaybeLocal<T> value)
+        : m_scriptState(scriptState)
+        , m_value(value.IsEmpty() ? nullptr : SharedPersistent<v8::Value>::create(value.ToLocalChecked(), scriptState->isolate()))
+    {
+        ASSERT(isEmpty() || m_scriptState);
+    }
+
     ScriptValue(const ScriptValue& value)
         : m_scriptState(value.m_scriptState)
         , m_value(value.m_value)
@@ -84,6 +92,12 @@ public:
         return m_scriptState ? m_scriptState->isolate() : v8::Isolate::GetCurrent();
     }
 
+    v8::Local<v8::Context> context() const
+    {
+        ASSERT(m_scriptState.get());
+        return m_scriptState->context();
+    }
+
     ScriptValue& operator=(const ScriptValue& value)
     {
         if (this != &value) {