Cleanup dart to string conversions.

Source/WebCore/bindings/dart/custom/DartMessageEventCustom.cpp

 // Copyright 2011, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //    * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //    * Redistributions in binary form must reproduce the above
@@ skipping 91 matching lines @@
     DART_UNIMPLEMENTED();
 }
 
 void initMessageEventCallback(Dart_NativeArguments args)
 {
     DartApiScope dartApiScope;
     Dart_Handle exception = 0;
     {
         MessageEvent* receiver = DartDOMWrapper::receiver<MessageEvent>(args);
 
-        const ParameterAdapter<String> typeArg(Dart_GetNativeArgument(args, 1));
-        if (!typeArg.conversionSuccessful()) {
-            exception = typeArg.exception();
+        DartStringAdapter typeArg = DartUtilities::dartToString(Dart_GetNativeArgument(args, 1), exception);
+        if (exception)
             goto fail;
-        }
 
         bool canBubbleArg = DartUtilities::dartToBool(Dart_GetNativeArgument(args, 2), exception);
         if (exception)
             goto fail;
 
         bool cancelableArg = DartUtilities::dartToBool(Dart_GetNativeArgument(args, 3), exception);
         if (exception)
             goto fail;
 
         RefPtr<SerializedScriptValue> dataArg = DartUtilities::dartToSerializedScriptValue(Dart_GetNativeArgument(args, 4), exception);
         if (exception)
             goto fail;
 
-        const ParameterAdapter<String> originArg(Dart_GetNativeArgument(args, 5));
-        if (!originArg.conversionSuccessful()) {
-            exception = originArg.exception();
+        DartStringAdapter originArg = DartUtilities::dartToString(Dart_GetNativeArgument(args, 5), exception);
+        if (exception)
             goto fail;
-        }
 
-        const ParameterAdapter<String> lastEventIdArg(Dart_GetNativeArgument(args, 6));
-        if (!lastEventIdArg.conversionSuccessful()) {
-            exception = lastEventIdArg.exception();
+        DartStringAdapter lastEventIdArg = DartUtilities::dartToString(Dart_GetNativeArgument(args, 6), exception);
+        if (exception)
             goto fail;
-        }
 
         DOMWindow* sourceArg = DartDOMWindow::toNative(Dart_GetNativeArgument(args, 7), exception);
         if (exception)
             goto fail;
 
         OwnPtr<MessagePortArray> portArray;
         if (!Dart_IsNull(Dart_GetNativeArgument(args, 8))) {
             portArray = adoptPtr(new MessagePortArray);
             ArrayBufferArray bufferArray;
             DartUtilities::toMessagePortArray(Dart_GetNativeArgument(args, 8), *portArray, bufferArray, exception);
@@ skipping 16 matching lines @@
 
 void webkitInitMessageEventCallback(Dart_NativeArguments)
 {
     // FIXME: proper implementation.
     DART_UNIMPLEMENTED();
 }
 
 }
 
 }