Removed the memory pool from the mixer.

webrtc/modules/audio_mixer/include/audio_mixer_defines.h

Index: webrtc/modules/audio_mixer/include/audio_mixer_defines.h
diff --git a/webrtc/modules/audio_mixer/include/audio_mixer_defines.h b/webrtc/modules/audio_mixer/include/audio_mixer_defines.h
index e204435c1a30f09114bf406967352769e359d9b8..01c26842b75728af4b5c0a18ab4cfc6c15578740 100644
--- a/webrtc/modules/audio_mixer/include/audio_mixer_defines.h
+++ b/webrtc/modules/audio_mixer/include/audio_mixer_defines.h
@@ -54,6 +54,11 @@ class MixerAudioSource {
   // Returns true if the participant was mixed this mix iteration.
   bool IsMixed() const;
 
+  // Indended use: the caller of GetAudioFrame* uses this method to
+  // provide an AudioFrame to this object. This decreases complexity
+  // and the need to allocate AudioFrames on the caller side.
+  AudioFrame* GetFramePointer() { return &_audio_frame; }
+
   // This function specifies the sampling frequency needed for the AudioFrame
   // for future GetAudioFrame(..) calls.
   virtual int32_t NeededFrequency(int32_t id) const = 0;
@@ -63,6 +68,11 @@ class MixerAudioSource {
  protected:
   MixerAudioSource();
   virtual ~MixerAudioSource();
+
+ private:
+  // This frame is intended to be passed to GetAudioFrame* for
+  // efficiency.
+  AudioFrame _audio_frame;

[ossu, 2016/07/06 11:49:37]

Seems to me the frame should be put in the implementing class, not in this one.
Also it should be spelled audio_frame_. :)

[aleloi, 2016/07/06 11:59:38]

You are right. I think I wanted to be consistent with the surrounding code or
something.

 };
 }  // namespace webrtc