Remove the last piece of deprecated synchronous IO code.

media/audio/win/audio_manager_win.cc

Index: media/audio/win/audio_manager_win.cc
diff --git a/media/audio/win/audio_manager_win.cc b/media/audio/win/audio_manager_win.cc
index eb05ca0547b19095cf97348ea5b78a443f324c20..23d089c4a2a44a657ae8f9854bfb2020680dd6cb 100644
--- a/media/audio/win/audio_manager_win.cc
+++ b/media/audio/win/audio_manager_win.cc
@@ -314,9 +314,8 @@ AudioParameters AudioManagerWin::GetInputStreamParameters(
   int user_buffer_size = GetUserBufferSize();
   if (user_buffer_size) {
     parameters.Reset(parameters.format(), parameters.channel_layout(),
-                     parameters.channels(), parameters.input_channels(),
-                     parameters.sample_rate(), parameters.bits_per_sample(),
-                     user_buffer_size);
+                     parameters.channels(), parameters.sample_rate(),
+                     parameters.bits_per_sample(), user_buffer_size);
   }
 
   return parameters;
@@ -422,7 +421,6 @@ AudioParameters AudioManagerWin::GetPreferredOutputStreamParameters(
   int sample_rate = 48000;
   int buffer_size = kFallbackBufferSize;
   int bits_per_sample = 16;
-  int input_channels = 0;
   int effects = AudioParameters::NO_EFFECTS;
   bool use_input_params = !core_audio_supported();
   if (core_audio_supported()) {
@@ -487,7 +485,7 @@ AudioParameters AudioManagerWin::GetPreferredOutputStreamParameters(
         }
       }
     }
-    input_channels = input_params.input_channels();
+
     effects |= input_params.effects();
     if (use_input_params) {
       // If WASAPI isn't supported we'll fallback to WaveOut, which will take
@@ -507,7 +505,7 @@ AudioParameters AudioManagerWin::GetPreferredOutputStreamParameters(
     buffer_size = user_buffer_size;
 
   return AudioParameters(
-      AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout, input_channels,
+      AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout,
       sample_rate, bits_per_sample, buffer_size, effects);
 }