Add basic support for "googDucking" to getUserMedia on Windows.

content/renderer/media/media_stream_dependency_factory.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/media/media_stream_dependency_factory.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 41 matching lines @@
 #include "media/base/android/media_codec_bridge.h"
 #endif
 
 namespace content {
 
 // Map of corresponding media constraints and platform effects.
 struct {
   const char* constraint;
   const media::AudioParameters::PlatformEffectsMask effect;
 } const kConstraintEffectMap[] = {
+  { content::kMediaStreamAudioDucking,
+    media::AudioParameters::DUCKING },
   { webrtc::MediaConstraintsInterface::kEchoCancellation,
-    media::AudioParameters::ECHO_CANCELLER},
+    media::AudioParameters::ECHO_CANCELLER },
 };
 
 // If any platform effects are available, check them against the constraints.
 // Disable effects to match false constraints, but if a constraint is true, set
 // the constraint to false to later disable the software effect.
 //
 // This function may modify both |constraints| and |effects|.
 void HarmonizeConstraintsAndEffects(RTCMediaConstraints* constraints,
                                     int* effects) {
   if (*effects != media::AudioParameters::NO_EFFECTS) {
@@ skipping 760 matching lines @@
 }
 
 void MediaStreamDependencyFactory::EnsureWebRtcAudioDeviceImpl() {
   if (audio_device_)
     return;
 
   audio_device_ = new WebRtcAudioDeviceImpl();
 }
 
 }  // namespace content