Optionally disable APM limiter in AudioMixer.

webrtc/modules/audio_mixer/audio_mixer_impl.h

Index: webrtc/modules/audio_mixer/audio_mixer_impl.h
diff --git a/webrtc/modules/audio_mixer/audio_mixer_impl.h b/webrtc/modules/audio_mixer/audio_mixer_impl.h
index 63bc7404d4f822119caaf3f3ed626a2ca1abb31f..8e6144b195783b5825dc621a953bb66953f69db3 100644
--- a/webrtc/modules/audio_mixer/audio_mixer_impl.h
+++ b/webrtc/modules/audio_mixer/audio_mixer_impl.h
@@ -18,6 +18,7 @@
 #include "webrtc/base/scoped_ref_ptr.h"
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/base/race_checker.h"
+#include "webrtc/modules/audio_mixer/frame_combiner.h"
 #include "webrtc/modules/audio_mixer/output_rate_calculator.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 #include "webrtc/modules/include/module_common_types.h"
@@ -48,9 +49,18 @@ class AudioMixerImpl : public AudioMixer {
   static const int kMaximumAmountOfMixedAudioSources = 3;
 
   static rtc::scoped_refptr<AudioMixerImpl> Create();
-  static rtc::scoped_refptr<AudioMixerImpl> CreateWithOutputRateCalculator(
+
+  // TODO(aleloi): remove this when dependencies have updated to
+  // use Create..AndLimiter instead. See bugs.webrtc.org/7167.
+  RTC_DEPRECATED static rtc::scoped_refptr<AudioMixerImpl>
+  CreateWithOutputRateCalculator(
       std::unique_ptr<OutputRateCalculator> output_rate_calculator);
 
+  static rtc::scoped_refptr<AudioMixerImpl>
+  CreateWithOutputRateCalculatorAndLimiter(
+      std::unique_ptr<OutputRateCalculator> output_rate_calculator,
+      bool use_limiter);
+
   ~AudioMixerImpl() override;
 
   // AudioMixer functions
@@ -66,8 +76,8 @@ class AudioMixerImpl : public AudioMixer {
   bool GetAudioSourceMixabilityStatusForTest(Source* audio_source) const;
 
  protected:
-  AudioMixerImpl(std::unique_ptr<AudioProcessing> limiter,
-                 std::unique_ptr<OutputRateCalculator> output_rate_calculator);
+  AudioMixerImpl(std::unique_ptr<OutputRateCalculator> output_rate_calculator,
+                 bool use_limiter);
 
  private:
   // Set mixing frequency through OutputFrequencyCalculator.
@@ -87,8 +97,6 @@ class AudioMixerImpl : public AudioMixer {
   bool RemoveAudioSourceFromList(Source* remove_audio_source,
                                  SourceStatusList* audio_source_list) const;
 
-  bool LimitMixedAudio(AudioFrame* mixed_audio) const;
-
   // The critical section lock guards audio source insertion and
   // removal, which can be done from any thread. The race checker
   // checks that mixing is done sequentially.
@@ -103,14 +111,8 @@ class AudioMixerImpl : public AudioMixer {
   // List of all audio sources. Note all lists are disjunct
   SourceStatusList audio_source_list_ GUARDED_BY(crit_);  // May be mixed.
 
-  // Determines if we will use a limiter for clipping protection during
-  // mixing.
-  bool use_limiter_ GUARDED_BY(race_checker_);
-
-  uint32_t time_stamp_ GUARDED_BY(race_checker_);
-
-  // Used for inhibiting saturation in mixing.
-  std::unique_ptr<AudioProcessing> limiter_ GUARDED_BY(race_checker_);
+  // Component that handles actual adding of audio frames.
+  FrameCombiner frame_combiner_ GUARDED_BY(race_checker_);
 
   RTC_DISALLOW_COPY_AND_ASSIGN(AudioMixerImpl);
 };