Cleanup dart to string conversions.

Source/WebCore/bindings/dart/custom/DartXMLHttpRequestCustom.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 54 matching lines @@
     Dart_ThrowException(exception);
     ASSERT_NOT_REACHED();
 }
 
 void openCallback(Dart_NativeArguments args)
 {
     DartApiScope dartApiScope;
     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)
             return;
         KURL fullURL = context->completeURL(url);
 
         ExceptionCode ec = 0;
         Dart_Handle arg3 = Dart_GetNativeArgument(args, 3);
         if (!Dart_IsNull(arg3)) {
             bool async = DartUtilities::dartToBool(arg3, exception);
             if (exception)
                 goto fail;
 
             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
                     receiver->open(method, fullURL, async, user, ec);
             } else
                 receiver->open(method, fullURL, async, ec);
         } else
             receiver->open(method, fullURL, ec);
 
         if (UNLIKELY(ec)) {
@@ skipping 35 matching lines @@
                 goto fail;
             receiver->send(asDOMFormData, ec);
 #if ENABLE(WEBGL) || ENABLE(BLOB)
         } else if (DartDOMWrapper::instanceOf<DartArrayBuffer>(arg1)) {
             ArrayBuffer* asArrayBuffer = DartArrayBuffer::toNative(arg1, exception);
             if (exception)
                 goto fail;
             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);
         }
 
         if (UNLIKELY(ec)) {
             exception = DartDOMWrapper::exceptionCodeToDartException(ec);
             goto fail;
         }
         return;
     }
 
@@ skipping 88 matching lines @@
     }
 
 fail:
     Dart_ThrowException(exception);
     ASSERT_NOT_REACHED();
 }
 
 } // DartXMLHttpRequestInternal
 
 } // WebCore