Cleanup dart to string conversions.

Source/WebCore/bindings/dart/DartNativeUtilities.cpp

Index: Source/WebCore/bindings/dart/DartNativeUtilities.cpp
diff --git a/Source/WebCore/bindings/dart/DartNativeUtilities.cpp b/Source/WebCore/bindings/dart/DartNativeUtilities.cpp
index 14725da91b4e6d41f249b33918b0ceb8b823cb6e..f4f2f8a1426ce612d18682d2823e0e2bfef6dca9 100644
--- a/Source/WebCore/bindings/dart/DartNativeUtilities.cpp
+++ b/Source/WebCore/bindings/dart/DartNativeUtilities.cpp
@@ -76,11 +76,9 @@ static void print(Dart_NativeArguments args)
     Dart_Handle exception = 0;
 
     {
-        const ParameterAdapter<String> message(Dart_GetNativeArgument(args, 0));
-        if (!message.conversionSuccessful()) {
-            exception = message.exception();
+        DartStringAdapter message = DartUtilities::dartToString(Dart_GetNativeArgument(args, 0), exception);
+        if (exception)
             goto fail;
-        }
 
         printf("[print]: %s\n", String(message).utf8().data());
         return;
@@ -96,11 +94,9 @@ static void npObjectRetrieve(Dart_NativeArguments args)
     DartApiScope dartApiScope;
     Dart_Handle exception = 0;
     {
-        const ParameterAdapter<String> key(Dart_GetNativeArgument(args, 0));
-        if (!key.conversionSuccessful()) {
-            exception = key.exception();
+        DartStringAdapter key = DartUtilities::dartToString(Dart_GetNativeArgument(args, 0), exception);
+        if (exception)
             goto fail;
-        }
 
         DartController* controller = DartController::retrieve(DartUtilities::scriptExecutionContext());
         NPObject* npObject = controller->npObject(key);
@@ -189,11 +185,9 @@ static void spawnDomIsolate(Dart_NativeArguments args)
         UNUSED_PARAM(result);
         RefPtr<DOMWindow> targetWindow(reinterpret_cast<DOMWindow*>(value));
 
-        const ParameterAdapter<String> entryPoint(Dart_GetNativeArgument(args, 1));
-        if (!entryPoint.conversionSuccessful()) {
-            exception = entryPoint.exception();
+        DartStringAdapter entryPoint = DartUtilities::dartToString(Dart_GetNativeArgument(args, 1), exception);
+        if (exception)
             goto fail;
-        }
 
         ScriptExecutionContext* context = DartUtilities::scriptExecutionContext();
         if (!context) {
@@ -240,7 +234,7 @@ Dart_NativeFunction domResolver(Dart_Handle name, int argumentCount)
     if (Dart_NativeFunction func = DartDOMStringMap::resolver(name, argumentCount))
         return func;
 
-    String str = DartUtilities::dartStringToString(name);
+    String str = DartUtilities::toString(name);
     if (argumentCount == 0 && str == "Utils_window")
         return topLevelWindow;
     if (argumentCount == 1 && str == "Utils_print")