Remove obsolete custom code

Source/bindings/dart/custom/DartClipboardCustom.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
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//    * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// 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 "DartClipboard.h"
-
-#include "DartElement.h"
-#include "core/dom/Element.h"
-#include "core/html/HTMLImageElement.h"
-
-namespace WebCore {
-
-namespace DartClipboardInternal {
-
-void setDragImageCallback(Dart_NativeArguments args)
-{
-    Dart_Handle exception = 0;
-    {
-        Clipboard* receiver = DartDOMWrapper::receiver<Clipboard>(args);
-
-        if (!receiver->isForDragAndDrop())
-            return;
-
-        Element* node = DartElement::toNative(Dart_GetNativeArgument(args, 1), exception);
-        if (exception)
-            goto fail;
-        if (!node || !node->isElementNode()) {
-            exception = Dart_NewStringFromCString("setDragImageFromElement: Invalid first argument");
-            goto fail;
-        }
-
-        int x = DartUtilities::dartToInt(Dart_GetNativeArgument(args, 2), exception);
-        if (exception)
-            goto fail;
-
-        int y = DartUtilities::dartToInt(Dart_GetNativeArgument(args, 3), exception);
-        if (exception)
-            goto fail;
-
-        DartExceptionState es;
-        receiver->setDragImage(node, x, y, es);
-        if (es.hadException()) {
-            exception = DartDOMWrapper::exceptionCodeToDartException(es);
-            goto fail;
-        }
-
-        return;
-    }
-
-fail:
-    Dart_ThrowException(exception);
-    ASSERT_NOT_REACHED();
-}
-
-}
-
-}