Add the copresence DirectiveHandler.

components/copresence/common/copresence_constants.cc

Index: components/copresence/common/copresence_constants.cc
diff --git a/components/copresence/common/copresence_constants.cc b/components/copresence/common/copresence_constants.cc
new file mode 100644
index 0000000000000000000000000000000000000000..86b648b2b5013c1774caaea7db97f4f0e95159b2
--- /dev/null
+++ b/components/copresence/common/copresence_constants.cc
@@ -0,0 +1,16 @@
+// 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/common/copresence_constants.h"
+
+namespace copresence {
+
+const int kDefaultRepetitions = 5;
+const float kDefaultSampleRate = 48000.0;

[xiyuan, 2014/07/25 21:02:08]

nit: 'f' for float literals to avoid compiler warning, e.g. 48000.0f

[rkc, 2014/07/28 21:01:59]

Done.

+const int kDefaultBitsPerSample = 16;
+const float kDefaultCarrierFrequency = 18500.0;

[xiyuan, 2014/07/25 21:02:08]

nit: 18500.0f

[rkc, 2014/07/28 21:01:59]

Done.

+const int kDefaultChannels = 2;
+const media::ChannelLayout kDefaultChannelLayout = media::CHANNEL_LAYOUT_STEREO;
+
+}  // namespace copresence