Set ImplementationName() correctly in webrtc::Video*coder implementations

We should set this field to distinguish HW codec implementations of Chromium
from SW codecs of WebRTC. googCodecName field already sets VP8/VP9/H264
information, so setting this field to a generic name "HW*coder" should be
enough.

Bug: 838739
Change-Id: I9936daef9a53b6f004ede357e37fd976ca0d9c9e
Reviewed-on: https://chromium-review.googlesource.com/1039023
Commit-Queue: Emircan Uysaler <emircan@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556167}

content/renderer/media/webrtc/rtc_video_decoder.cc

@@ -536,6 +536,10 @@ void RTCVideoDecoder::NotifyError(media::VideoDecodeAccelerator::Error error) {
   ++vda_error_counter_;
 }
 
+const char* RTCVideoDecoder::ImplementationName() const {
+  return "ExternalDecoder";
+}
+
 void RTCVideoDecoder::RequestBufferDecode() {
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
   if (!vda_)

content/renderer/media/webrtc/rtc_video_decoder.h

@@ -92,6 +92,7 @@ class CONTENT_EXPORT RTCVideoDecoder
   void NotifyFlushDone() override;
   void NotifyResetDone() override;
   void NotifyError(media::VideoDecodeAccelerator::Error error) override;
+  const char* ImplementationName() const override;
 
  private:
   // Metadata of a bitstream buffer.

content/renderer/media/webrtc/rtc_video_encoder.cc

@@ -154,6 +154,8 @@ class RTCVideoEncoder::Impl
 
   webrtc::VideoCodecType video_codec_type() const { return video_codec_type_; }
 
+  static const char* ImplementationName() { return "ExternalEncoder"; }
+
   // media::VideoEncodeAccelerator::Client implementation.
   void RequireBitstreamBuffers(unsigned int input_count,
                                const gfx::Size& input_coded_size,
@@ -767,6 +769,7 @@ void RTCVideoEncoder::Impl::ReturnEncodedImage(
   webrtc::CodecSpecificInfo info;
   memset(&info, 0, sizeof(info));
   info.codecType = video_codec_type_;
+  info.codec_name = ImplementationName();
   if (video_codec_type_ == webrtc::kVideoCodecVP8) {
     info.codecSpecific.VP8.pictureId = picture_id;
     info.codecSpecific.VP8.tl0PicIdx = -1;
@@ -938,4 +941,8 @@ bool RTCVideoEncoder::SupportsNativeHandle() const {
   return true;
 }
 
+const char* RTCVideoEncoder::ImplementationName() const {
+  return RTCVideoEncoder::Impl::ImplementationName();
+}
+
 }  // namespace content

content/renderer/media/webrtc/rtc_video_encoder.h

@@ -59,6 +59,7 @@ class CONTENT_EXPORT RTCVideoEncoder : public webrtc::VideoEncoder {
   int32_t SetChannelParameters(uint32_t packet_loss, int64_t rtt) override;
   int32_t SetRates(uint32_t new_bit_rate, uint32_t frame_rate) override;
   bool SupportsNativeHandle() const override;
+  const char* ImplementationName() const override;
 
  private:
   class Impl;