FilePlayer: Remove backwards compatibility stuff that we no longer need

This includes renaming NewFilePlayer to CreateFilePlayer.

Review-Url: https://codereview.webrtc.org/2319123003
Cr-Commit-Position: refs/heads/master@{#14128}
diff --git a/webrtc/modules/utility/source/file_player.cc b/webrtc/modules/utility/source/file_player.cc
index 75b7214..bf6d269 100644
--- a/webrtc/modules/utility/source/file_player.cc
+++ b/webrtc/modules/utility/source/file_player.cc
@@ -371,7 +371,7 @@
 
 }  // namespace
 
-std::unique_ptr<FilePlayer> FilePlayer::NewFilePlayer(
+std::unique_ptr<FilePlayer> FilePlayer::CreateFilePlayer(
     uint32_t instanceID,
     FileFormats fileFormat) {
   switch (fileFormat) {
@@ -390,13 +390,4 @@
   }
 }
 
-FilePlayer* FilePlayer::CreateFilePlayer(uint32_t instanceID,
-                                         FileFormats fileFormat) {
-  return FilePlayer::NewFilePlayer(instanceID, fileFormat).release();
-}
-
-void FilePlayer::DestroyFilePlayer(FilePlayer* player) {
-  delete player;
-}
-
 }  // namespace webrtc