Remove duplicated headers from core/

Source/core/platform/DragImage.cpp

 /*
  * Copyright (C) 2007 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 21 matching lines @@
 #include "core/platform/graphics/GraphicsContext.h"
 #include "core/platform/graphics/Image.h"
 #include "core/platform/graphics/ImageBuffer.h"
 #include "core/platform/graphics/StringTruncator.h"
 #include "core/platform/graphics/skia/NativeImageSkia.h"
 #include "platform/fonts/FontDescription.h"
 #include "platform/fonts/FontMetrics.h"
 #include "platform/geometry/FloatPoint.h"
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/IntPoint.h"
-#include "platform/geometry/IntSize.h"
 #include "platform/graphics/Color.h"
 #include "platform/graphics/TextRun.h"
 #include "platform/transforms/AffineTransform.h"
 #include "platform/weborigin/KURL.h"
 #include "skia/ext/image_operations.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkMatrix.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/RefPtr.h"
 #include "wtf/text/WTFString.h"
@@ skipping 205 matching lines @@
             *pixel = SkPreMultiplyARGB(
                 SkColorGetA(*pixel) * fraction,
                 SkColorGetR(*pixel),
                 SkColorGetG(*pixel),
                 SkColorGetB(*pixel));
         }
     }
 }
 
 } // namespace WebCore