Added functions on libjingle API to start and stop the recording of an RtcEventLog.

talk/media/webrtc/webrtcvoiceengine.cc

Index: talk/media/webrtc/webrtcvoiceengine.cc
diff --git a/talk/media/webrtc/webrtcvoiceengine.cc b/talk/media/webrtc/webrtcvoiceengine.cc
index 5130232bca4ce880ba5fea277fb0b58d7e39fefa..d39654589d2c043d3bf5671590cdb1a0b19060e1 100644
--- a/talk/media/webrtc/webrtcvoiceengine.cc
+++ b/talk/media/webrtc/webrtcvoiceengine.cc
@@ -50,6 +50,7 @@
 #include "webrtc/base/logging.h"
 #include "webrtc/base/stringencode.h"
 #include "webrtc/base/stringutils.h"
+#include "webrtc/call/rtc_event_log.h"
 #include "webrtc/common.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 
@@ -1336,6 +1337,26 @@ void WebRtcVoiceEngine::StopAecDump() {
   }
 }
 
+bool WebRtcVoiceEngine::StartRtcEventLog(rtc::PlatformFile file) {
+  FILE* event_log_file = rtc::FdopenPlatformFileForWriting(file);
+  if (!event_log_file) {
+    LOG(LS_ERROR) << "Could not open AEC dump file stream.";

[Henrik Grunell WebRTC, 2015/10/02 10:23:42]

Update text.

[ivoc, 2015/10/07 14:27:27]

Done.

+    if (!rtc::ClosePlatformFile(file))

[pthatcher1, 2015/10/06 20:49:09]

{}s please

[ivoc, 2015/10/07 14:27:27]

Done.

+      LOG(LS_WARNING) << "Could not close file.";
+    return false;
+  }
+  if (voe_wrapper_->codec()->GetEventLog()->StartLogging(event_log_file) != 0) {
+    LOG_RTCERR0(StartLogging);

[pthatcher1, 2015/10/06 20:49:09]

Why does this go through the voice engine?  Why doesn't it go straight from the
ChannelManager/MediaController to webrtc::Call?  It's not audio-specific, is it?

[ivoc, 2015/10/07 14:27:27]

See other reply. For now VoE owns the logging object, but that will change soon.

[pthatcher1, 2015/10/07 15:59:23]

Then can you put a comment in PeerConnectionFactory explaining this? 
- How the method really shouldn't belong there, but it has to because.... 
- TODO(...): Move this into being PeerConnection => MediaController =>
webrtc::Call.  

Or something like that.

[ivoc, 2015/10/08 16:20:17]

Good idea, I added some comments there like you suggested.

+    fclose(event_log_file);
+    return false;
+  }
+  return true;
+}
+
+void WebRtcVoiceEngine::StopRtcEventLog() {
+  voe_wrapper_->codec()->GetEventLog()->StopLogging();
+}
+
 int WebRtcVoiceEngine::CreateVoiceChannel(VoEWrapper* voice_engine_wrapper) {
   return voice_engine_wrapper->base()->CreateChannel(voe_config_);
 }