Remove the last piece of deprecated synchronous IO code.

media/audio/android/audio_manager_android.cc

Index: media/audio/android/audio_manager_android.cc
diff --git a/media/audio/android/audio_manager_android.cc b/media/audio/android/audio_manager_android.cc
index 48f203ab74e8bb1d3bc4ab395fc301757db3a7a6..0d1fa0dbd95c4e83d0d3cdff64e2cbb02f64c7bd 100644
--- a/media/audio/android/audio_manager_android.cc
+++ b/media/audio/android/audio_manager_android.cc
@@ -274,13 +274,11 @@ AudioParameters AudioManagerAndroid::GetPreferredOutputStreamParameters(
   int sample_rate = GetNativeOutputSampleRate();
   int buffer_size = GetOptimalOutputFrameSize(sample_rate, 2);
   int bits_per_sample = 16;
-  int input_channels = 0;
   if (input_params.IsValid()) {
     // Use the client's input parameters if they are valid.
     sample_rate = input_params.sample_rate();
     bits_per_sample = input_params.bits_per_sample();
     channel_layout = input_params.channel_layout();
-    input_channels = input_params.input_channels();
     buffer_size = GetOptimalOutputFrameSize(
         sample_rate, ChannelLayoutToChannelCount(channel_layout));
   }
@@ -290,7 +288,7 @@ AudioParameters AudioManagerAndroid::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, AudioParameters::NO_EFFECTS);
 }