Delete unused features of rtc::FilesystemInterface.

webrtc/base/unixfilesystem.h

Index: webrtc/base/unixfilesystem.h
diff --git a/webrtc/base/unixfilesystem.h b/webrtc/base/unixfilesystem.h
index 78351e8489919a074a62545dca237b0c531db1c0..e3710ec4827388602c8fabc3f9de2ea65f310267 100644
--- a/webrtc/base/unixfilesystem.h
+++ b/webrtc/base/unixfilesystem.h
@@ -39,10 +39,6 @@ class UnixFilesystem : public FilesystemInterface {
   FileStream* OpenFile(const Pathname& filename,
                        const std::string& mode) override;
 
-  // Atomically creates an empty file accessible only to the current user if one
-  // does not already exist at the given path, otherwise fails.
-  bool CreatePrivateFile(const Pathname& filename) override;
-
   // This will attempt to delete the file located at filename.
   // It will fail with VERIY if you pass it a non-existant file, or a directory.
   bool DeleteFile(const Pathname& filename) override;
@@ -65,7 +61,6 @@ class UnixFilesystem : public FilesystemInterface {
   // file or directory, which will be moved recursively.
   // Returns true if function succeeds.
   bool MoveFile(const Pathname& old_path, const Pathname& new_path) override;
-  bool MoveFolder(const Pathname& old_path, const Pathname& new_path) override;
 
   // This copies a file from old_path to _new_path where "file" can be a plain
   // file or directory, which will be copied recursively.
@@ -99,9 +94,6 @@ class UnixFilesystem : public FilesystemInterface {
                    FileTimeType which,
                    time_t* time) override;
 
-  // Returns the path to the running application.
-  bool GetAppPathname(Pathname* path) override;
-
   bool GetAppDataFolder(Pathname* path, bool per_user) override;
 
   // Get a temporary folder that is unique to the current user and application.
@@ -109,9 +101,6 @@ class UnixFilesystem : public FilesystemInterface {
 
   bool GetDiskFreeSpace(const Pathname& path, int64_t* freebytes) override;
 
-  // Returns the absolute path of the current directory.
-  Pathname GetCurrentDirectory() override;
-
  private:
 #if defined(WEBRTC_ANDROID) || defined(WEBRTC_MAC)
   static char* provided_app_data_folder_;