FileReader.result attribute should use IDL union types to avoid using custom binding.

Source/core/fileapi/FileReader.cpp

 /*
  * Copyright (C) 2010 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 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/fileapi/FileReader.h"
 
 #include "bindings/core/v8/ExceptionState.h"
+#include "bindings/core/v8/UnionTypesCore.h"
 #include "core/dom/CrossThreadTask.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/events/ProgressEvent.h"
 #include "core/fileapi/File.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "platform/Logging.h"
 #include "platform/Supplementable.h"
@@ skipping 312 matching lines @@
     ThrottlingController::FinishReaderType finalStep = ThrottlingController::removeReader(executionContext(), this);
 
     fireEvent(EventTypeNames::error);
     fireEvent(EventTypeNames::abort);
     fireEvent(EventTypeNames::loadend);
 
     // All possible events have fired and we're done, no more pending activity.
     ThrottlingController::finishReader(executionContext(), this, finalStep);
 }
 
+void FileReader::result(StringOrArrayBuffer& resultAttribute) const
+{
+    if (!m_loader || m_error)
+        return;
+
+    if (m_readType == FileReaderLoader::ReadAsArrayBuffer)
+        resultAttribute.setArrayBuffer(m_loader->arrayBufferResult());
+    else
+        resultAttribute.setString(m_loader->stringResult());
+}
+
 void FileReader::terminate()
 {
     if (m_loader) {
         m_loader->cancel();
         m_loader = nullptr;
     }
     m_state = DONE;
     m_loadingState = LoadingStateNone;
 }
 
@@ skipping 72 matching lines @@
     }
 
     if (m_loader->totalBytes() >= 0)
         dispatchEvent(ProgressEvent::create(type, true, m_loader->bytesLoaded(), m_loader->totalBytes()));
     else
         dispatchEvent(ProgressEvent::create(type, false, m_loader->bytesLoaded(), 0));
 
     InspectorInstrumentation::traceAsyncCallbackCompleted(cookie);
 }
 
-PassRefPtr<DOMArrayBuffer> FileReader::arrayBufferResult() const
-{
-    if (!m_loader || m_error)
-        return nullptr;
-    return m_loader->arrayBufferResult();
-}
-
-String FileReader::stringResult()
-{
-    if (!m_loader || m_error)
-        return String();
-    return m_loader->stringResult();
-}
-
 void FileReader::trace(Visitor* visitor)
 {
     visitor->trace(m_error);
     RefCountedGarbageCollectedEventTargetWithInlineData<FileReader>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink