Reland: Tie kWebRtcH264WithOpenH264FFmpeg and kEnableWebRtcHWH264Encoding flags on Mac

content/renderer/media/rtc_video_encoder_factory.cc

Index: content/renderer/media/rtc_video_encoder_factory.cc
diff --git a/content/renderer/media/rtc_video_encoder_factory.cc b/content/renderer/media/rtc_video_encoder_factory.cc
index 194a236fb5bb97a92eff3379ff6e40252933245f..7e99b7c13865ac2358e374554adf50c0ec4ce2b7 100644
--- a/content/renderer/media/rtc_video_encoder_factory.cc
+++ b/content/renderer/media/rtc_video_encoder_factory.cc
@@ -6,6 +6,7 @@
 
 #include "base/command_line.h"
 #include "content/public/common/content_switches.h"
+#include "content/public/common/feature_h264_with_openh264_ffmpeg.h"
 #include "content/renderer/media/rtc_video_encoder.h"
 #include "media/gpu/ipc/client/gpu_video_encode_accelerator_host.h"
 #include "media/renderers/gpu_video_accelerator_factories.h"
@@ -32,7 +33,13 @@ void VEAToWebRTCCodecs(
         webrtc::kVideoCodecVP8, "VP8", width, height, fps));
   } else if (profile.profile >= media::H264PROFILE_MIN &&
              profile.profile <= media::H264PROFILE_MAX) {
-    if (cmd_line->HasSwitch(switches::kEnableWebRtcHWH264Encoding)) {
+    bool webrtc_h264_enabled = false;
+#if BUILDFLAG(RTC_USE_H264) && defined(OS_MACOSX)
+    webrtc_h264_enabled =
+        base::FeatureList::IsEnabled(kWebRtcH264WithOpenH264FFmpeg);
+#endif  // BUILDFLAG(RTC_USE_H264) && defined(OS_MACOSX)
+    if (cmd_line->HasSwitch(switches::kEnableWebRtcHWH264Encoding) ||
+        webrtc_h264_enabled) {

[pbos, 2016/04/24 18:37:17]

I don't think we should hook this into whether SW H264 is enabled or not,
pushing both of these at the same time seems like it could be problematic to me.
It also makes it harder to test OpenH264/FFmpeg on platforms where hardware is
supported.

Isn't kEnableWebRtcHWH264Encoding sufficient? Otherwise, could you add a
separate flag?

       codecs->push_back(cricket::WebRtcVideoEncoderFactory::VideoCodec(
           webrtc::kVideoCodecH264, "H264", width, height, fps));
     }