Looking up device id by session id for AudioRendererMixerInput

content/renderer/media/audio_renderer_mixer_manager.h

 // Copyright (c) 2012 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 CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_
 #define CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_
 
 #include <map>
 #include <string>
 #include <utility>
 
 #include "base/macros.h"
 #include "base/synchronization/lock.h"
 #include "content/common/content_export.h"
+#include "media/audio/audio_manager_base.h"
 #include "media/audio/audio_parameters.h"
 #include "media/base/output_device.h"
 #include "url/origin.h"
 
 namespace media {
 class AudioHardwareConfig;
 class AudioRendererMixer;
 class AudioRendererMixerInput;
 class AudioRendererSink;
 }
@@ skipping 19 matching lines @@
   ~AudioRendererMixerManager();
 
   // Creates an AudioRendererMixerInput with the proper callbacks necessary to
   // retrieve an AudioRendererMixer instance from AudioRendererMixerManager.
   // |source_render_frame_id| refers to the RenderFrame containing the entity
   // rendering the audio.  Caller must ensure AudioRendererMixerManager outlives
   // the returned input. |device_id| and |security_origin| identify the output
   // device to use
   media::AudioRendererMixerInput* CreateInput(
       int source_render_frame_id,
+      int session_id,

[Henrik Grunell, 2016/03/08 21:09:57]

Is |session_id| optional or compulsory? Seems like we only care about it if
|device_id| is empty. Add info in the comment.

[o1ka, 2016/04/05 15:13:38]

Done.

       const std::string& device_id,
       const url::Origin& security_origin);
 
   // Returns a mixer instance based on AudioParameters; an existing one if one
   // with the provided AudioParameters exists or a new one if not.
   media::AudioRendererMixer* GetMixer(int source_render_frame_id,
                                       const media::AudioParameters& params,
                                       const std::string& device_id,
                                       const url::Origin& security_origin,
                                       media::OutputDeviceStatus* device_status);
@@ skipping 31 matching lines @@
         return a.source_render_frame_id < b.source_render_frame_id;
       if (a.params.channels() != b.params.channels())
         return a.params.channels() < b.params.channels();
 
       // Ignore effects(), bits_per_sample(), format(), and frames_per_buffer(),
       // these parameters do not affect mixer reuse.  All AudioRendererMixer
       // units disable FIFO, so frames_per_buffer() can be safely ignored.
       if (a.params.channel_layout() != b.params.channel_layout())
         return a.params.channel_layout() < b.params.channel_layout();
 
+      if (media::AudioManagerBase::IsDefaultDeviceId(a.device_id) &&
+          media::AudioManagerBase::IsDefaultDeviceId(b.device_id)) {
+        // Both device IDs represent the same default device => do not compare
+        // them; the default device is always authorized => ignoring security
+        // origin.
+        return false;
+      }
+
       if (a.device_id != b.device_id)
-        return a.device_id < b.device_id;
+        return (a.device_id < b.device_id);

[o1ka, 2016/03/07 15:25:49]

nit: I'll remove brackets.

[o1ka, 2016/04/05 15:13:38]

Done.

 
       return a.security_origin < b.security_origin;
     }
   };
 
   // Map of MixerKey to <AudioRendererMixer, Count>.  Count allows
   // AudioRendererMixerManager to keep track explicitly (v.s. RefCounted which
   // is implicit) of the number of outstanding AudioRendererMixers.
   struct AudioRendererMixerReference {
     media::AudioRendererMixer* mixer;
@@ skipping 10 matching lines @@
   static media::AudioParameters GetHardwareOutputParams(
       int render_frame_id,
       int session_id,
       const std::string& device_id,
       const url::Origin& security_origin);
 
   // Active mixers.
   AudioRendererMixerMap mixers_;
   base::Lock mixers_lock_;
 
-  media::AudioRendererSink* sink_for_testing_;
-
   DISALLOW_COPY_AND_ASSIGN(AudioRendererMixerManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_