Update internal SW codecs to return unique_ptrs

TBR=stefan@webrtc.org

Bug: webrtc:7925
Change-Id: I84239b071a2608d928f09b06809090eec5eafb14
Reviewed-on: https://webrtc-review.googlesource.com/21165
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20650}
diff --git a/media/engine/internalencoderfactory.cc b/media/engine/internalencoderfactory.cc
index 23c85cb..fa6783f 100644
--- a/media/engine/internalencoderfactory.cc
+++ b/media/engine/internalencoderfactory.cc
@@ -64,11 +64,11 @@
       webrtc::PayloadStringToCodecType(codec.name);
   switch (codec_type) {
     case webrtc::kVideoCodecH264:
-      return webrtc::H264Encoder::Create(codec);
+      return webrtc::H264Encoder::Create(codec).release();
     case webrtc::kVideoCodecVP8:
-      return webrtc::VP8Encoder::Create();
+      return webrtc::VP8Encoder::Create().release();
     case webrtc::kVideoCodecVP9:
-      return webrtc::VP9Encoder::Create();
+      return webrtc::VP9Encoder::Create().release();
     default:
       return nullptr;
   }