Stop playing/recording when not needed.

components/copresence/handlers/directive_handler.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_HANDLERS_DIRECTIVE_HANDLER_H_
 #define COMPONENTS_COPRESENCE_HANDLERS_DIRECTIVE_HANDLER_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
-#include "components/copresence/handlers/audio/audio_directive_list.h"
+#include "components/copresence/handlers/audio/audio_directive_handler.h"
 #include "components/copresence/mediums/audio/audio_recorder.h"
 
 namespace copresence {
 
-class AudioDirectiveHandler;
 class Directive;
 
 // The directive handler manages transmit and receive directives
 // given to it by the client.
 class DirectiveHandler {
  public:
   DirectiveHandler();
   virtual ~DirectiveHandler();
 
   // Initialize the |audio_handler_| with the appropriate callbacks.
   // This function must be called before any others.
   // TODO(ckehoe): Instead of this, use a static Create() method
   //               and make the constructor private.
   virtual void Initialize(
       const AudioRecorder::DecodeSamplesCallback& decode_cb,
-      const AudioDirectiveList::EncodeTokenCallback& encode_cb);
+      const AudioDirectiveHandler::EncodeTokenCallback& encode_cb);
 
   // Adds a directive to handle.
   virtual void AddDirective(const copresence::Directive& directive);
   // Removes any directives associated with the given operation id.
   virtual void RemoveDirectives(const std::string& op_id);
 
+  const std::string& CurrentAudibleToken();

[xiyuan, 2014/08/12 18:57:50]

nit: const std::string& CurrentAudibleToken() const; and the one below.

[rkc, 2014/08/13 00:29:00]

Done.

+  const std::string& CurrentInaudibleToken();
+
  private:
   scoped_ptr<AudioDirectiveHandler> audio_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(DirectiveHandler);
 };
 
 }  // namespace copresence
 
 #endif  // COMPONENTS_COPRESENCE_HANDLERS_DIRECTIVE_HANDLER_H_