Added an "enable-audio-processor" flag and WebRtcAudioProcessor class

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 4b76e075f277ccf2e3ded81904e9e4e8ae8d9043..e8d3b706b1d80474642ff0bbb8dca6937eb3d5d0 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -914,10 +914,14 @@ const char kZygoteCmdPrefix[]               = "zygote-cmd-prefix";
 const char kZygoteProcess[]                 = "zygote";
 
 #if defined(ENABLE_WEBRTC)
-// Disable WebRTC device enumeration.
+// Enables audio processing in a MediaStreamTrack ? When this flag is on, aec,
+// Ns and AGC will be done per MediaStreamTrack instead of in PeerConnection.
+const char kEnableAudioTrackProcessing[]    = "enable-audio-processor";
+
+// Disables WebRTC device enumeration.
 const char kDisableDeviceEnumeration[]      = "disable-device-enumeration";
 
-// Disable WebRTC DataChannels SCTP wire protocol support.
+// Disables WebRTC DataChannels SCTP wire protocol support.
 const char kDisableSCTPDataChannels[]       = "disable-sctp-data-channels";
 
 // Disables HW decode acceleration for WebRTC.
@@ -933,7 +937,7 @@ const char kDisableWebRtcHWEncoding[]       = "disable-webrtc-hw-encoding";
 // Enables WebRTC AEC recordings.
 const char kEnableWebRtcAecRecordings[]     = "enable-webrtc-aec-recordings";
 
-// Enable WebRTC to open TCP server sockets.
+// Enables WebRTC to open TCP server sockets.
 const char kEnableWebRtcTcpServerSocket[]   = "enable-webrtc-tcp-server-socket";
 
 // Enables VP8 HW encode acceleration for WebRTC.