Pass selected cricket::VideoCodec down to internal H264 encoder

Pass the selected cricket::VideoCodec to H264EncoderImpl::H264EncoderImpl. The cricket::VideoCodec contains relevant information for H264 about selected profile and packetization mode.

BUG=chromium:600254,webrtc:6402, webrtc:6337

Review-Url: https://codereview.webrtc.org/2474993002
Cr-Commit-Position: refs/heads/master@{#15270}
diff --git a/webrtc/media/engine/internalencoderfactory.cc b/webrtc/media/engine/internalencoderfactory.cc
index db30b66..e714e5a 100644
--- a/webrtc/media/engine/internalencoderfactory.cc
+++ b/webrtc/media/engine/internalencoderfactory.cc
@@ -69,7 +69,7 @@
           .value_or(webrtc::kVideoCodecUnknown);
   switch (codec_type) {
     case webrtc::kVideoCodecH264:
-      return webrtc::H264Encoder::Create();
+      return webrtc::H264Encoder::Create(codec);
     case webrtc::kVideoCodecVP8:
       return webrtc::VP8Encoder::Create();
     case webrtc::kVideoCodecVP9: