Android: enable WebRTC HW H264 with a flag by default

content/public/browser/gpu_utils.cc

Index: content/public/browser/gpu_utils.cc
diff --git a/content/public/browser/gpu_utils.cc b/content/public/browser/gpu_utils.cc
index 7ac9c72396a2b8ba4677285c3b9dc820d2273f6b..5d77e94bcd1d6afc57f2f1d61e40a457cf5fe86c 100644
--- a/content/public/browser/gpu_utils.cc
+++ b/content/public/browser/gpu_utils.cc
@@ -46,9 +46,7 @@ const gpu::GpuPreferences GetGpuPreferencesFromCommandLine() {
 #endif
 #if BUILDFLAG(ENABLE_WEBRTC)
   gpu_preferences.disable_web_rtc_hw_encoding =

[piman, 2016/12/07 19:16:33]

nit: update the name of this field too, to accurately represent what it does.
E.g. disable_web_rtc_hw_vp8_encoding

[braveyao, 2016/12/07 20:29:53]

It's better to keep it as is. Because either VP8 or H264 HW encoding is enabled,
|disable_web_rtc_hw_encoding| won't be true and GPU will create VEA according to
it. So I suppose the name is right here.

[piman, 2016/12/07 20:35:33]

The logic here is wrong then. If H264 HW encoding is enabled, and VP8 is
disabled, disable_web_rtc_hw_encoding will be set to true, and we will *not* use
HW encoding.

[braveyao, 2016/12/07 21:34:02]

Thanks so much! I neglected that case...
Done. 

-      command_line->HasSwitch(switches::kDisableWebRtcHWEncoding) &&
-      command_line->GetSwitchValueASCII(switches::kDisableWebRtcHWEncoding)
-          .empty();
+      command_line->HasSwitch(switches::kDisableWebRtcHWVP8Encoding);
 #endif
 #if defined(OS_WIN)
   uint32_t enable_accelerated_vpx_decode_val =