Add metadata to media::VideoFrame and plumb it through IPC/MediaStream.

media/base/BUILD.gn

 # 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.
 
 import("//build/config/android/config.gni")
 import("//build/config/arm.gni")
 import("//build/config/ui.gni")
 import("//build/config/linux/pkg_config.gni")
 import("//media/media_options.gni")
 
@@ skipping 154 matching lines @@
     "video_capture_types.cc",
     "video_capture_types.h",
     "video_capturer_source.cc",
     "video_capturer_source.h",
     "video_decoder.cc",
     "video_decoder.h",
     "video_decoder_config.cc",
     "video_decoder_config.h",
     "video_frame.cc",
     "video_frame.h",
+    "video_frame_metadata.cc",
+    "video_frame_metadata.h",
     "video_frame_pool.cc",
     "video_frame_pool.h",
     "video_renderer.cc",
     "video_renderer.h",
     "video_rotation.h",
     "video_util.cc",
     "video_util.h",
     "wall_clock_time_source.cc",
     "wall_clock_time_source.h",
     "yuv_convert.cc",
@@ skipping 80 matching lines @@
 
 # Minimal media component for media/cast on iOS.
 config("base_for_cast_ios_dependent_config") {
   defines = [ "MEDIA_FOR_CAST_IOS" ]
 }
 
 source_set("base_for_cast_ios") {
   sources = [
     "video_frame.cc",
     "video_frame.h",
+    "video_frame_metadata.cc",
+    "video_frame_metadata.h",
   ]
   configs += [
     "//build/config/compiler:no_size_t_to_int_warning",
     "//media:media_config",
   ]
   all_dependent_configs = [ ":base_for_cast_ios_dependent_config" ]
 }
 
 source_set("test_support") {
   testonly = true
@@ skipping 195 matching lines @@
       if (is_posix) {
         yasm_flags += [ "-DELF" ]
         if (current_cpu == "x64") {
           # TODO(ajwong): Why isn't this true in mac?
           yasm_flags += [ "-DPIC" ]
         }
       }
     }
   }
 }