Add the copresence DirectiveHandler.

components/copresence/copresence_constants.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/copresence/public/copresence_constants.h"
+
+namespace copresence {
+
+const int kDefaultRepetitions = 5;
+const float kDefaultSampleRate = 48000.0f;
+const int kDefaultBitsPerSample = 16;
+const float kDefaultCarrierFrequency = 18500.0f;
+const int kDefaultChannels = 2;
+const media::ChannelLayout kDefaultChannelLayout = media::CHANNEL_LAYOUT_STEREO;
+
+}  // namespace copresence