Delete unused Filesystem methods GetAppDataFolder and GetDiskFreeSpace.

webrtc/base/unixfilesystem.h

Index: webrtc/base/unixfilesystem.h
diff --git a/webrtc/base/unixfilesystem.h b/webrtc/base/unixfilesystem.h
index d6dfed547b5fba664fb7e27bd2ab6309c76826d0..8338e5cd0bb504c4f30d4183f91b25a72309a4bd 100644
--- a/webrtc/base/unixfilesystem.h
+++ b/webrtc/base/unixfilesystem.h
@@ -94,13 +94,9 @@ class UnixFilesystem : public FilesystemInterface {
                    FileTimeType which,
                    time_t* time) override;
 
-  bool GetAppDataFolder(Pathname* path, bool per_user) override;
-
   // Get a temporary folder that is unique to the current user and application.
   bool GetAppTempFolder(Pathname* path) override;
 
-  bool GetDiskFreeSpace(const Pathname& path, int64_t* freebytes) override;
-
  private:
 #if defined(WEBRTC_ANDROID) || defined(WEBRTC_MAC)
   static char* provided_app_data_folder_;