Implement File constructor.

Source/core/html/FormDataList.cpp

 /*
  * Copyright (C) 2005, 2006, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 97 matching lines @@
                 else
                     contentType = value.blob()->type();
                 FormDataBuilder::addContentTypeToMultiPartHeader(header, contentType.latin1());
             }
 
             FormDataBuilder::finishMultiPartHeader(header);
 
             // Append body
             formData->appendData(header.data(), header.size());
             if (value.blob()) {
-                if (value.blob()->isFile()) {
+                if (value.blob()->hasBackingFile()) {
                     File* file = toFile(value.blob());
                     // Do not add the file if the path is empty.
                     if (!file->path().isEmpty())
                         formData->appendFile(file->path());
                     if (!file->fileSystemURL().isEmpty())
                         formData->appendFileSystemURL(file->fileSystemURL());
                 } else {
                     formData->appendBlob(value.blob()->uuid(), value.blob()->blobDataHandle());
                 }
             } else {
@@ skipping 10 matching lines @@
         }
     }
 
     if (isMultiPartForm)
         FormDataBuilder::addBoundaryToMultiPartHeader(encodedData, formData->boundary().data(), true);
 
     formData->appendData(encodedData.data(), encodedData.size());
 }
 
 } // namespace