Add basic resample support to WASAPIAudioInputStream.

media/audio/win/audio_low_latency_input_win.h

Index: media/audio/win/audio_low_latency_input_win.h
diff --git a/media/audio/win/audio_low_latency_input_win.h b/media/audio/win/audio_low_latency_input_win.h
index 09aeaf9976520f012abe79822ef3d7b0eb5619d5..94307ade840cd2a734a7a2d06e944c9714f8b340 100644
--- a/media/audio/win/audio_low_latency_input_win.h
+++ b/media/audio/win/audio_low_latency_input_win.h
@@ -82,6 +82,7 @@ namespace media {
 
 class AudioBus;
 class AudioManagerWin;
+class MultiChannelResampler;
 
 // AudioInputStream implementation using Windows Core Audio APIs.
 class MEDIA_EXPORT WASAPIAudioInputStream
@@ -125,6 +126,10 @@ class MEDIA_EXPORT WASAPIAudioInputStream
   HRESULT InitializeAudioEngine();
   void ReportOpenResult() const;
 
+  // Provides input to the MultiChannelResampler.  Called by the resampler when
+  // more data is necessary.
+  void ProvideInput(int resampler_frame_delay, AudioBus* audio_bus);
+
   // Used to track down where we fail during initialization which at the
   // moment seems to be happening frequently and we're not sure why.
   // The reason might be expected (e.g. trying to open "default" on a machine
@@ -146,7 +151,8 @@ class MEDIA_EXPORT WASAPIAudioInputStream
     OPEN_RESULT_SET_EVENT_HANDLE = 11,
     OPEN_RESULT_NO_CAPTURE_CLIENT = 12,
     OPEN_RESULT_NO_AUDIO_VOLUME = 13,
-    OPEN_RESULT_MAX = OPEN_RESULT_NO_AUDIO_VOLUME
+    OPEN_RESULT_OK_WITH_RESAMPLING = 14,
+    OPEN_RESULT_MAX = OPEN_RESULT_OK_WITH_RESAMPLING
   };
 
   // Our creator, the audio manager needs to be notified when we close.
@@ -243,6 +249,11 @@ class MEDIA_EXPORT WASAPIAudioInputStream
   // indicates that we need to unmute the system audio when stopping capturing.
   bool mute_done_ = false;
 
+  // If the caller requires resampling (should only be in exceptional cases and
+  // ideally, never), we support using a MultiChannelResampler.
+  std::unique_ptr<MultiChannelResampler> resampler_;
+  std::unique_ptr<AudioBus> resample_bus_;
+
   DISALLOW_COPY_AND_ASSIGN(WASAPIAudioInputStream);
 };