FileWrapper[Impl] modifications and actually remove the "Impl" class.

webrtc/modules/video_coding/utility/ivf_file_writer.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 121 matching lines @@
   }
   LOG(LS_WARNING) << "Created IVF file " << file_name_
                   << " for codec data of type " << codec_name
                   << " at resolution " << width_ << " x " << height_
                   << ", using " << (using_capture_timestamps_ ? "1" : "90")
                   << "kHz clock resolution.";
   return true;
 }
 
 bool IvfFileWriter::WriteFrame(const EncodedImage& encoded_image) {
-  RTC_DCHECK(file_->Open());
+  RTC_DCHECK(file_->is_open());
 
   if (num_frames_ == 0 && !InitFromFirstFrame(encoded_image))
     return false;
 
   if ((encoded_image._encodedWidth > 0 || encoded_image._encodedHeight > 0) &&
       (encoded_image._encodedHeight != height_ ||
        encoded_image._encodedWidth != width_)) {
     LOG(LS_WARNING)
         << "Incomig frame has diffferent resolution then previous: (" << width_
         << "x" << height_ << ") -> (" << encoded_image._encodedWidth << "x"
@@ skipping 18 matching lines @@
       !file_->Write(encoded_image._buffer, encoded_image._length)) {
     LOG(LS_ERROR) << "Unable to write frame to file " << file_name_;
     return false;
   }
 
   ++num_frames_;
   return true;
 }
 
 bool IvfFileWriter::Close() {
-  if (!file_->Open())
+  if (!file_->is_open())
     return false;
 
   if (num_frames_ == 0) {
     // No frame written to file, close and remove it entirely if possible.
     file_->CloseFile();
     if (remove(file_name_.c_str()) != 0)
       LOG(LS_WARNING) << "Failed to remove empty IVF file " << file_name_;
 
     return true;
   }
 
-  return WriteHeader() && (file_->CloseFile() == 0);
+  bool ret = WriteHeader();
+  file_->CloseFile();
+  return ret;
 }
 
 }  // namespace webrtc