Reland "Use kEnableWebRtcHWH264Encoding flag when SW fallback is available"

content/renderer/media/gpu/rtc_video_encoder_factory.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/gpu/rtc_video_encoder_factory.h"
 
 #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/gpu/rtc_video_encoder.h"
@@ skipping 15 matching lines @@
   const int fps = profile.max_framerate_numerator;
   DCHECK_EQ(profile.max_framerate_denominator, 1U);
 
   const base::CommandLine* cmd_line = base::CommandLine::ForCurrentProcess();
   if (profile.profile >= media::VP8PROFILE_MIN &&
       profile.profile <= media::VP8PROFILE_MAX) {
     codecs->push_back(cricket::WebRtcVideoEncoderFactory::VideoCodec(
         webrtc::kVideoCodecVP8, "VP8", width, height, fps));
   } else if (profile.profile >= media::H264PROFILE_MIN &&
              profile.profile <= media::H264PROFILE_MAX) {
-    bool webrtc_h264_enabled = false;
-#if BUILDFLAG(RTC_USE_H264) && defined(OS_MACOSX)
-    webrtc_h264_enabled =
+    // Enable H264 HW encode for WebRTC when SW fallback is available, which is
+    // checked by kWebRtcH264WithOpenH264FFmpeg flag. This check should be
+    // removed when SW implementation is fully enabled.
+    // kEnableWebRtcHWH264Encoding flag is only enabled for extensions, and
+    // can be used without SW fallback.
+    bool webrtc_h264_sw_enabled = false;
+#if BUILDFLAG(RTC_USE_H264)
+    webrtc_h264_sw_enabled =
         base::FeatureList::IsEnabled(kWebRtcH264WithOpenH264FFmpeg);
-#endif  // BUILDFLAG(RTC_USE_H264) && defined(OS_MACOSX)
+#endif  // BUILDFLAG(RTC_USE_H264)
     if (cmd_line->HasSwitch(switches::kEnableWebRtcHWH264Encoding) ||
-        webrtc_h264_enabled) {
+        webrtc_h264_sw_enabled) {
       codecs->push_back(cricket::WebRtcVideoEncoderFactory::VideoCodec(
           webrtc::kVideoCodecH264, "H264", width, height, fps));
     }
   }
 }
 
 }  // anonymous namespace
 
 RTCVideoEncoderFactory::RTCVideoEncoderFactory(
     media::GpuVideoAcceleratorFactories* gpu_factories)
@@ skipping 19 matching lines @@
 RTCVideoEncoderFactory::codecs() const {
   return codecs_;
 }
 
 void RTCVideoEncoderFactory::DestroyVideoEncoder(
     webrtc::VideoEncoder* encoder) {
   delete encoder;
 }
 
 }  // namespace content