media/capture: Adding WebmMuxer class and unittests

media/media_options.gni

 # Copyright 2014 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.
 
 declare_args() {
   # Allows distributions to link pulseaudio directly (DT_NEEDED) instead of
   # using dlopen. This helps with automated detection of ABI mismatches and
   # prevents silent errors.
   link_pulseaudio = false
 
   # Enable usage of FFmpeg within the media library. Used for most software
   # based decoding, demuxing, and sometimes optimized FFTs. If disabled,
   # implementors must provide their own demuxers and decoders.
   media_use_ffmpeg = true
 
   # Enable usage of libvpx within the media library. Used for software based
   # decoding of VP9 and VP8A type content.
   media_use_libvpx = true
 
-  # Neither Android nor iOS use ffmpeg or libvpx.
+  # Enable libwebm for multiplexing video and audio for JS recording API.
+  media_use_libwebm = true
+
+  # Neither Android nor iOS use ffmpeg, libvpx nor libwebm.
   if (is_android || is_ios) {
     media_use_ffmpeg = false
     media_use_libvpx = false
+    media_use_libwebm = false
   }
 
   # Override to dynamically link the cras (ChromeOS audio) library.
   use_cras = false
 
   # Enables runtime selection of PulseAudio library.
   use_pulseaudio = false
 
   # Enables runtime selection of ALSA library for audio.
   use_alsa = false
@@ skipping 14 matching lines @@
   # Experiment to enable mojo media application: http://crbug.com/431776
   # Valid options are:
   # - "none": Do not use mojo media application.
   # - "browser": Use mojo media application hosted in the browser process.
   # - "utility": Use mojo media application hosted in the utility process.
   enable_mojo_media = "none"
 
   # TODO(GYP): This should be a platform define.
   is_openbsd = false
 }