Fix Windows audio capturer to handle AUDCLNT_BUFFERFLAGS_SILENT flag.

remoting/host/audio_capturer_win.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 "remoting/host/audio_capturer_win.h"
 
 #include <windows.h>
 #include <avrt.h>
 #include <mmreg.h>
 #include <mmsystem.h>
@@ skipping 224 matching lines @@
       return;
     }
 
     BYTE* data;
     UINT32 frames;
     DWORD flags;
     hr = audio_capture_client_->GetBuffer(&data, &frames, &flags, NULL, NULL);
     if (FAILED(hr))
       break;
 
-    if (!silence_detector_.IsSilence(
+    if ((flags & AUDCLNT_BUFFERFLAGS_SILENT) == 0 &&
+        !silence_detector_.IsSilence(
             reinterpret_cast<const int16*>(data), frames * kChannels)) {
       scoped_ptr<AudioPacket> packet =
           scoped_ptr<AudioPacket>(new AudioPacket());
       packet->add_data(data, frames * wave_format_ex_->nBlockAlign);
       packet->set_encoding(AudioPacket::ENCODING_RAW);
       packet->set_sampling_rate(sampling_rate_);
       packet->set_bytes_per_sample(AudioPacket::BYTES_PER_SAMPLE_2);
       packet->set_channels(AudioPacket::CHANNELS_STEREO);
 
       callback_.Run(packet.Pass());
@@ skipping 19 matching lines @@
 
 bool AudioCapturer::IsSupported() {
   return true;
 }
 
 scoped_ptr<AudioCapturer> AudioCapturer::Create() {
   return scoped_ptr<AudioCapturer>(new AudioCapturerWin());
 }
 
 }  // namespace remoting