Only populate line number in case parsing synchronously.

Source/core/inspector/ConsoleMessage.cpp

Index: Source/core/inspector/ConsoleMessage.cpp
diff --git a/Source/core/inspector/ConsoleMessage.cpp b/Source/core/inspector/ConsoleMessage.cpp
index 6045374b6ff5b0bfbdf0af0d3a700110193f3e7b..93650f96f582ef8ad423cb183112ff8d2c82df0e 100644
--- a/Source/core/inspector/ConsoleMessage.cpp
+++ b/Source/core/inspector/ConsoleMessage.cpp
@@ -29,7 +29,6 @@ ConsoleMessage::ConsoleMessage(MessageSource source,
     , m_columnNumber(columnNumber)
     , m_requestIdentifier(0)
     , m_timestamp(WTF::currentTime())
-    , m_async(false)
     , m_workerProxy(nullptr)
 {
 }
@@ -136,16 +135,6 @@ void ConsoleMessage::setTimestamp(double timestamp)
     m_timestamp = timestamp;
 }
 
-bool ConsoleMessage::isAsync() const
-{
-    return m_async;
-}
-
-void ConsoleMessage::markAsAsync()
-{
-    m_async = true;
-}
-
 MessageSource ConsoleMessage::source() const
 {
     return m_source;