Remove the last piece of deprecated synchronous IO code.

content/renderer/renderer_webkitplatformsupport_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/renderer_webkitplatformsupport_impl.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 733 matching lines @@
   if (input_device_id.isNull() ||
       !base::StringToInt(base::UTF16ToUTF8(input_device_id), &session_id)) {
     if (input_channels > 0)
       DLOG(WARNING) << "createAudioDevice(): request for audio input ignored";
 
     input_channels = 0;
   }
 
   media::AudioParameters params(
       media::AudioParameters::AUDIO_PCM_LOW_LATENCY,
-      layout, input_channels,
-      static_cast<int>(sample_rate), 16, buffer_size,
+      layout, static_cast<int>(sample_rate), 16, buffer_size,
       media::AudioParameters::NO_EFFECTS);
 
   return new RendererWebAudioDeviceImpl(params, callback, session_id);
 }
 
 #if defined(OS_ANDROID)
 bool RendererWebKitPlatformSupportImpl::loadAudioResource(
     blink::WebAudioBus* destination_bus, const char* audio_file_data,
     size_t data_size) {
   return DecodeAudioFileData(destination_bus,
@@ skipping 421 matching lines @@
 void RendererWebKitPlatformSupportImpl::MockBatteryStatusChangedForTesting(
     const blink::WebBatteryStatus& status) {
   PlatformEventObserverBase* observer =
       platform_event_observers_.Lookup(blink::WebPlatformEventBattery);
   if (!observer)
     return;
   observer->SendFakeDataForTesting((void*)&status);
 }
 
 }  // namespace content