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/modules/audio_processing/agc/gain_map_internal.h

@@ -0,0 +1,275 @@
+/*
+ *  Copyright (c) 2013 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_MODULES_AUDIO_PROCESSING_AGC_GAIN_MAP_INTERNAL_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_AGC_GAIN_MAP_INTERNAL_H_
+
+static const int kGainMapSize = 256;
+// Uses parameters: si = 2, sf = 0.25, D = 8/256
+static const int kGainMap[kGainMapSize] = {
+  -56,
+  -54,
+  -52,
+  -50,
+  -48,
+  -47,
+  -45,
+  -43,
+  -42,
+  -40,
+  -38,
+  -37,
+  -35,
+  -34,
+  -33,
+  -31,
+  -30,
+  -29,
+  -27,
+  -26,
+  -25,
+  -24,
+  -23,
+  -22,
+  -20,
+  -19,
+  -18,
+  -17,
+  -16,
+  -15,
+  -14,
+  -14,
+  -13,
+  -12,
+  -11,
+  -10,
+  -9,
+  -8,
+  -8,
+  -7,
+  -6,
+  -5,
+  -5,
+  -4,
+  -3,
+  -2,
+  -2,
+  -1,
+  0,
+  0,
+  1,
+  1,
+  2,
+  3,
+  3,
+  4,
+  4,
+  5,
+  5,
+  6,
+  6,
+  7,
+  7,
+  8,
+  8,
+  9,
+  9,
+  10,
+  10,
+  11,
+  11,
+  12,
+  12,
+  13,
+  13,
+  13,
+  14,
+  14,
+  15,
+  15,
+  15,
+  16,
+  16,
+  17,
+  17,
+  17,
+  18,
+  18,
+  18,
+  19,
+  19,
+  19,
+  20,
+  20,
+  21,
+  21,
+  21,
+  22,
+  22,
+  22,
+  23,
+  23,
+  23,
+  24,
+  24,
+  24,
+  24,
+  25,
+  25,
+  25,
+  26,
+  26,
+  26,
+  27,
+  27,
+  27,
+  28,
+  28,
+  28,
+  28,
+  29,
+  29,
+  29,
+  30,
+  30,
+  30,
+  30,
+  31,
+  31,
+  31,
+  32,
+  32,
+  32,
+  32,
+  33,
+  33,
+  33,
+  33,
+  34,
+  34,
+  34,
+  35,
+  35,
+  35,
+  35,
+  36,
+  36,
+  36,
+  36,
+  37,
+  37,
+  37,
+  38,
+  38,
+  38,
+  38,
+  39,
+  39,
+  39,
+  39,
+  40,
+  40,
+  40,
+  40,
+  41,
+  41,
+  41,
+  41,
+  42,
+  42,
+  42,
+  42,
+  43,
+  43,
+  43,
+  44,
+  44,
+  44,
+  44,
+  45,
+  45,
+  45,
+  45,
+  46,
+  46,
+  46,
+  46,
+  47,
+  47,
+  47,
+  47,
+  48,
+  48,
+  48,
+  48,
+  49,
+  49,
+  49,
+  49,
+  50,
+  50,
+  50,
+  50,
+  51,
+  51,
+  51,
+  51,
+  52,
+  52,
+  52,
+  52,
+  53,
+  53,
+  53,
+  53,
+  54,
+  54,
+  54,
+  54,
+  55,
+  55,
+  55,
+  55,
+  56,
+  56,
+  56,
+  56,
+  57,
+  57,
+  57,
+  57,
+  58,
+  58,
+  58,
+  58,
+  59,
+  59,
+  59,
+  59,
+  60,
+  60,
+  60,
+  60,
+  61,
+  61,
+  61,
+  61,
+  62,
+  62,
+  62,
+  62,
+  63,
+  63,
+  63,
+  63,
+  64
+};
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AGC_GAIN_MAP_INTERNAL_H_