Implements the GetSignalLevel and GetStats interface for the local audio track.

content/renderer/media/webrtc/webrtc_local_audio_track_adapter.cc

Index: content/renderer/media/webrtc/webrtc_local_audio_track_adapter.cc
diff --git a/content/renderer/media/webrtc/webrtc_local_audio_track_adapter.cc b/content/renderer/media/webrtc/webrtc_local_audio_track_adapter.cc
index 56729197f1b18a1db5ba95a4d77ee8214fed3324..b1bde99a258b9555502a34a02c61353d58937be6 100644
--- a/content/renderer/media/webrtc/webrtc_local_audio_track_adapter.cc
+++ b/content/renderer/media/webrtc/webrtc_local_audio_track_adapter.cc
@@ -5,8 +5,10 @@
 #include "content/renderer/media/webrtc/webrtc_local_audio_track_adapter.h"
 
 #include "base/logging.h"
+#include "content/renderer/media/media_stream_audio_processor.h"
 #include "content/renderer/media/webrtc/webrtc_audio_sink_adapter.h"
 #include "content/renderer/media/webrtc_local_audio_track.h"
+#include "third_party/libjingle/source/talk/app/webrtc/mediastreaminterface.h"
 
 namespace content {
 
@@ -27,7 +29,8 @@ WebRtcLocalAudioTrackAdapter::WebRtcLocalAudioTrackAdapter(
     webrtc::AudioSourceInterface* track_source)
     : webrtc::MediaStreamTrack<webrtc::AudioTrackInterface>(label),
       owner_(NULL),
-      track_source_(track_source) {
+      track_source_(track_source),
+      signal_level_(0) {
 }
 
 WebRtcLocalAudioTrackAdapter::~WebRtcLocalAudioTrackAdapter() {
@@ -39,6 +42,12 @@ void WebRtcLocalAudioTrackAdapter::Initialize(WebRtcLocalAudioTrack* owner) {
   owner_ = owner;
 }
 
+void WebRtcLocalAudioTrackAdapter::SetAudioProcessor(
+    const scoped_refptr<MediaStreamAudioProcessor>& processor) {
+  base::AutoLock auto_lock(lock_);
+  audio_processor_ = processor;
+}
+
 std::string WebRtcLocalAudioTrackAdapter::kind() const {
   return kAudioTrackKind;
 }
@@ -75,13 +84,26 @@ void WebRtcLocalAudioTrackAdapter::RemoveSink(
   }
 }
 
+bool WebRtcLocalAudioTrackAdapter::GetSignalLevel(int* level) {
+  base::AutoLock auto_lock(lock_);
+  *level = signal_level_;
+  return true;
+}
+
+talk_base::scoped_refptr<webrtc::AudioProcessorInterface>
+WebRtcLocalAudioTrackAdapter::GetAudioProcessor() {
+  base::AutoLock auto_lock(lock_);
+  return audio_processor_.get();
+}
+
 std::vector<int> WebRtcLocalAudioTrackAdapter::VoeChannels() const {
   base::AutoLock auto_lock(lock_);
   return voe_channels_;
 }
 
 void WebRtcLocalAudioTrackAdapter::SetSignalLevel(int signal_level) {
-  // TODO(xians): Implements this.
+  base::AutoLock auto_lock(lock_);
+  signal_level_ = signal_level;
 }
 
 void WebRtcLocalAudioTrackAdapter::AddChannel(int channel_id) {