Add polling and audio check to copresence.

components/copresence/public/copresence_constants.h

 // 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.
 
 #ifndef COMPONENTS_COPRESENCE_PUBLIC_COPRESENCE_CONSTANTS_
 #define COMPONENTS_COPRESENCE_PUBLIC_COPRESENCE_CONSTANTS_
 
+#include <string>
+#include <vector>
+
+#include "base/callback_forward.h"
+#include "base/memory/ref_counted.h"
 #include "media/base/channel_layout.h"
 
+namespace media {
+class AudioBusRefCounted;
+}
+
 namespace copresence {
 
 // Audio constants. Currently used from the AudioPlayer/AudioRecorder.
 // TODO(rkc): Make these values configurable then remove them from here.
 // Number of repetitions of the audio token in one sequence of samples.
 extern const int kDefaultRepetitions;
 
 // The default sample rate. We need to ensure that both the recorder and the
 // player on _all platforms use the same rate.
 extern const float kDefaultSampleRate;
@@ skipping 11 matching lines @@
 // Particularly, these are used to index the directive lists in the
 // audio manager, so do not change these enums without changing
 // audio_directive_list.[h|cc].
 enum AudioType {
   AUDIBLE = 0,
   INAUDIBLE = 1,
   BOTH = 2,
   AUDIO_TYPE_UNKNOWN = 3,
 };
 
+struct AudioToken {
+  AudioToken(const std::string& token, bool audible)
+      : token(token), audible(audible) {}
+  std::string token;
+  bool audible;
+};
+
+// These callbacks are used from various places in Copresence.
+
+// Generic callback to indicate a boolean success or failure.
+using SuccessCallback = base::Callback<void(bool)>;

[xiyuan, 2014/11/06 21:27:50]

Are we allowed to use "using" in this scoped in a header file? Why not using
typedef?

[rkc, 2014/11/06 21:45:05]

New C++11 rules (http://chromium-cpp.appspot.com/). From "Aliases", "Use instead
of typedef, unless the header needs to be compatible with C."

[xiyuan, 2014/11/06 21:51:12]

Good to know. Apparently, I don't follow chromium-dev close enough. :p

+
+// Callback to pass around found tokens.
+// Arguments:
+// const std::vector<AudioToken>& tokens - List of found tokens.
+using TokensCallback = base::Callback<void(const std::vector<AudioToken>&)>;
+
+// Callback to receive encoded samples from Whispernet.
+// AudioType type: Type of audio encoding - AUDIBLE or INAUDIBLE.
+// const std::string& token: The token that we encoded.
+// const scoped_refptr<media::AudioBusRefCounted>& samples - Encoded samples.
+using SamplesCallback =
+    base::Callback<void(AudioType,
+                        const std::string&,
+                        const scoped_refptr<media::AudioBusRefCounted>&)>;
 }  // namespace copresence
 
 #endif  // COMPONENTS_COPRESENCE_PUBLIC_COPRESENCE_CONSTANTS_