Expose codec implementation names in stats.

webrtc/video/video_encoder.cc

Index: webrtc/video/video_encoder.cc
diff --git a/webrtc/video/video_encoder.cc b/webrtc/video/video_encoder.cc
index 305406b6c0fdbe5fc73bba684b4db53013e0a6b9..cdb9ab587ae6c8a00ccf7c87883f5645f7ec62ea 100644
--- a/webrtc/video/video_encoder.cc
+++ b/webrtc/video/video_encoder.cc
@@ -134,6 +134,12 @@ bool VideoEncoderSoftwareFallbackWrapper::SupportsNativeHandle() const {
   return encoder_->SupportsNativeHandle();
 }
 
+const char* VideoEncoderSoftwareFallbackWrapper::ImplementationName() const {
+  if (fallback_encoder_)
+    return fallback_encoder_->ImplementationName();

[stefan-webrtc, 2015/10/16 07:47:03]

Should we add "fallback-" to the string here?

[pbos-webrtc, 2015/10/16 13:12:05]

Not unless we can know when an implementation is changed. I don't want to do any
string manipulation per frame. I added "software-fallback" since I think that's
more informative than "libvpx" when we've tried to do VP8 but failed.

[stefan-webrtc, 2015/10/22 09:33:34]

You don't have to manipulate the string for every frame. If you know you are
using the fallback encoder you should use the fallback encoder string, right? Or
do you mean that the fallback encoder implementation may change? In that case
maybe we should have a method to get the type of encoder so that we can check if
it has changed?

[pbos-webrtc, 2015/10/22 15:11:21]

Done, constructing the string once we start using the fallback encoder/decoder.

+  return encoder_->ImplementationName();
+}
+
 int VideoEncoderSoftwareFallbackWrapper::GetTargetFramerate() {
   if (fallback_encoder_)
     return fallback_encoder_->GetTargetFramerate();