Android: enable WebRTC HW H264 with a flag by default

content/public/browser/gpu_utils.cc

 // Copyright 2016 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/public/browser/gpu_utils.h"
 
 #include "base/command_line.h"
 #include "base/strings/string_number_conversions.h"
 #include "content/public/common/content_switches.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
@@ skipping 27 matching lines @@
       command_line->HasSwitch(switches::kInProcessGPU);
   gpu_preferences.ui_prioritize_in_gpu_process =
       command_line->HasSwitch(switches::kUIPrioritizeInGpuProcess);
   gpu_preferences.disable_accelerated_video_decode =
       command_line->HasSwitch(switches::kDisableAcceleratedVideoDecode);
 #if defined(OS_CHROMEOS)
   gpu_preferences.disable_vaapi_accelerated_video_encode =
       command_line->HasSwitch(switches::kDisableVaapiAcceleratedVideoEncode);
 #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 =
       gpu::GpuPreferences::VPX_VENDOR_MICROSOFT;
   if (GetUintFromSwitch(command_line, switches::kEnableAcceleratedVpxDecode,
                         &enable_accelerated_vpx_decode_val)) {
     gpu_preferences.enable_accelerated_vpx_decode =
         static_cast<gpu::GpuPreferences::VpxDecodeVendors>(
             enable_accelerated_vpx_decode_val);
   }
@@ skipping 47 matching lines @@
   gpu_preferences.enable_gpu_service_tracing =
       command_line->HasSwitch(switches::kEnableGPUServiceTracing);
   gpu_preferences.use_passthrough_cmd_decoder =
       command_line->HasSwitch(switches::kUsePassthroughCmdDecoder);
   // Some of these preferences are set or adjusted in
   // GpuDataManagerImplPrivate::AppendGpuCommandLine.
   return gpu_preferences;
 }
 
 }  // namespace content