Add polling and audio check to copresence.

components/copresence/public/copresence_constants.h

Index: components/copresence/public/copresence_constants.h
diff --git a/components/copresence/public/copresence_constants.h b/components/copresence/public/copresence_constants.h
index 07c38cf0bcca34fe10d168d36fdf504c9a148b7d..fa0b4390022abbc4958bbbf4e607630ce947c01a 100644
--- a/components/copresence/public/copresence_constants.h
+++ b/components/copresence/public/copresence_constants.h
@@ -5,8 +5,17 @@
 #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.
@@ -38,6 +47,31 @@ enum AudioType {
   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)>;
+
+// 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.
+// const std::string& token: The token that we encoded.
+// AudioType type: Type of audio encoding - AUDIBLE or INAUDIBLE.
+// 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_