Use CanvasImageSource union type instead of overloading

Source/core/frame/ImageBitmapTest.cpp

 /*
  * Copyright (c) 2013, 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/frame/ImageBitmap.h"
 
 #include "SkPixelRef.h" // FIXME: qualify this skia header file.
+#include "bindings/core/v8/UnionTypesCore.h"
 #include "core/dom/Document.h"
 #include "core/fetch/ImageResource.h"
 #include "core/fetch/MemoryCache.h"
 #include "core/fetch/MockImageResourceClient.h"
 #include "core/fetch/ResourcePtr.h"
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLImageElement.h"
+#include "core/html/HTMLVideoElement.h"
 #include "core/html/canvas/CanvasRenderingContext2D.h"
 #include "platform/graphics/BitmapImage.h"
 #include "platform/graphics/skia/NativeImageSkia.h"
 #include "platform/heap/Handle.h"
 #include "platform/network/ResourceRequest.h"
 #include "wtf/OwnPtr.h"
 
 #include <gtest/gtest.h>
 
 namespace blink {
@@ skipping 148 matching lines @@
     RefPtrWillBeRawPtr<HTMLCanvasElement> canvasElement = HTMLCanvasElement::create(*Document::create().get());
     canvasElement->setHeight(40);
     canvasElement->setWidth(40);
     RefPtrWillBeRawPtr<ImageBitmap> imageBitmapDerived = nullptr;
     {
         RefPtrWillBeRawPtr<ImageBitmap> imageBitmapFromCanvas = ImageBitmap::create(canvasElement.get(), IntRect(0, 0, canvasElement->width(), canvasElement->height()));
         imageBitmapDerived = ImageBitmap::create(imageBitmapFromCanvas.get(), IntRect(0, 0, 20, 20));
     }
     CanvasRenderingContext* context = canvasElement->getContext("2d");
     TrackExceptionState exceptionState;
-    toCanvasRenderingContext2D(context)->drawImage(imageBitmapDerived.get(), 0, 0, exceptionState);
+    CanvasImageSourceUnion imageSource;
+    imageSource.setImageBitmap(imageBitmapDerived);
+    toCanvasRenderingContext2D(context)->drawImage(imageSource, 0, 0, exceptionState);
 }
 
 } // namespace