Update audio_processing module

Corresponds to upstream commit 524e9b043e7e86fd72353b987c9d5f6a1ebf83e1

Update notes:

 * Pull in third party license file

 * Replace .gypi files with BUILD.gn to keep track of what changes
   upstream

 * Bunch of new filse pulled in as dependencies

 * Won't build yet due to changes needed on top of these

webrtc/system_wrappers/source/file_impl.h

@@ -0,0 +1,69 @@
+/*
+ *  Copyright (c) 2011 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.
+ */
+
+#ifndef WEBRTC_SYSTEM_WRAPPERS_SOURCE_FILE_IMPL_H_
+#define WEBRTC_SYSTEM_WRAPPERS_SOURCE_FILE_IMPL_H_
+
+#include <stdio.h>
+
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/system_wrappers/interface/file_wrapper.h"
+
+namespace webrtc {
+
+class RWLockWrapper;
+
+class FileWrapperImpl : public FileWrapper {
+ public:
+  FileWrapperImpl();
+  ~FileWrapperImpl() override;
+
+  int FileName(char* file_name_utf8, size_t size) const override;
+
+  bool Open() const override;
+
+  int OpenFile(const char* file_name_utf8,
+               bool read_only,
+               bool loop = false,
+               bool text = false) override;
+
+  int OpenFromFileHandle(FILE* handle,
+                         bool manage_file,
+                         bool read_only,
+                         bool loop = false) override;
+
+  int CloseFile() override;
+  int SetMaxFileSize(size_t bytes) override;
+  int Flush() override;
+
+  int Read(void* buf, size_t length) override;
+  bool Write(const void* buf, size_t length) override;
+  int WriteText(const char* format, ...) override;
+  int Rewind() override;
+
+ private:
+  int CloseFileImpl();
+  int FlushImpl();
+
+  rtc::scoped_ptr<RWLockWrapper> rw_lock_;
+
+  FILE* id_;
+  bool managed_file_handle_;
+  bool open_;
+  bool looping_;
+  bool read_only_;
+  size_t max_size_in_bytes_;  // -1 indicates file size limitation is off
+  size_t size_in_bytes_;
+  char file_name_utf8_[kMaxFileNameSize];
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_SYSTEM_WRAPPERS_SOURCE_FILE_IMPL_H_