Cleanup dart to string conversions.

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

Index: Source/WebCore/bindings/dart/custom/DartXMLHttpRequestCustom.cpp
diff --git a/Source/WebCore/bindings/dart/custom/DartXMLHttpRequestCustom.cpp b/Source/WebCore/bindings/dart/custom/DartXMLHttpRequestCustom.cpp
index b6313bdd2aeb377101151049317dd2cf4ace9662..deb80213afc08c7c0a34984fdeaf91a2561cac73 100644
--- a/Source/WebCore/bindings/dart/custom/DartXMLHttpRequestCustom.cpp
+++ b/Source/WebCore/bindings/dart/custom/DartXMLHttpRequestCustom.cpp
@@ -72,16 +72,12 @@ void openCallback(Dart_NativeArguments args)
     Dart_Handle exception = 0;
     {
         XMLHttpRequest* receiver = DartDOMWrapper::receiver<XMLHttpRequest>(args);
-        const ParameterAdapter<String> method(Dart_GetNativeArgument(args, 1));
-        if (!method.conversionSuccessful()) {
-            exception = method.exception();
+        DartStringAdapter method = DartUtilities::dartToString(Dart_GetNativeArgument(args, 1), exception);
+        if (exception)
             goto fail;
-        }
-        const ParameterAdapter<String> url(Dart_GetNativeArgument(args, 2));
-        if (!url.conversionSuccessful()) {
-            exception = url.exception();
+        DartStringAdapter url = DartUtilities::dartToString(Dart_GetNativeArgument(args, 2), exception);
+        if (exception)
             goto fail;
-        }
 
         ScriptExecutionContext* context = DartUtilities::scriptExecutionContext();
         if (!context)
@@ -97,19 +93,15 @@ void openCallback(Dart_NativeArguments args)
 
             Dart_Handle arg4 = Dart_GetNativeArgument(args, 4);
             if (!Dart_IsNull(arg4)) {
-                const ParameterAdapter<String> user(arg4);
-                if (!user.conversionSuccessful()) {
-                    exception = user.exception();
+                DartStringAdapter user = DartUtilities::dartToString(arg4, exception);
+                if (exception)
                     goto fail;
-                }
 
                 Dart_Handle arg5 = Dart_GetNativeArgument(args, 5);
                 if (!Dart_IsNull(arg5)) {
-                    const ParameterAdapter<String> passwd(arg5);
-                    if (!passwd.conversionSuccessful()) {
-                        exception = passwd.exception();
+                    DartStringAdapter passwd = DartUtilities::dartToString(arg5, exception);
+                    if (exception)
                         goto fail;
-                    }
 
                     receiver->open(method, fullURL, async, user, passwd, ec);
                 } else
@@ -165,11 +157,9 @@ void sendCallback(Dart_NativeArguments args)
             receiver->send(asArrayBuffer, ec);
 #endif
         } else {
-            const ParameterAdapter<String> asString(arg1);
-            if (!asString.conversionSuccessful()) {
-                exception = asString.exception();
+            DartStringAdapter asString = DartUtilities::dartToString(arg1, exception);
+            if (exception)
                 goto fail;
-            }
             receiver->send(asString, ec);
         }