Add a snapshot of flutter/engine/src/build to our sdk

build/config/features.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.
+
+# This file contains Chrome-feature-related build flags (see ui.gni for
+# UI-related ones). These should theoretically be moved to the build files of
+# the features themselves.
+#
+# However, today we have many "bad" dependencies on some of these flags from,
+# e.g. base, so they need to be global to match the GYP configuration. Also,
+# anything that needs a grit define must be in either this file or ui.gni.
+#
+# PLEASE TRY TO AVOID ADDING FLAGS TO THIS FILE in cases where grit isn't
+# required. See the declare_args block of BUILDCONFIG.gn for advice on how
+# to set up feature flags.
+
+import("//build/config/chrome_build.gni")
+if (is_android) {
+  import("//build/config/android/config.gni")
+}
+
+declare_args() {
+  # Multicast DNS.
+  enable_mdns = is_win || is_linux
+
+  enable_plugins = !is_android && !is_ios
+
+  # Enables Native Client support.
+  # TODO(GYP): Get NaCl linking on other platforms.
+  # Also, see if we can always get rid of enable_nacl_untrusted and
+  # enable_pnacl and always build them if enable_nacl is true.
+  # The "is_nacl" part of the condition is needed to ensure that
+  # the untrusted code is built properly; arguably it should be
+  # guarded by "is_nacl" directly rather than enable_nacl_untrusted, but
+  # this will go away when Mac and Win are working and we can just use
+  # the commented out logic.
+  # Eventually we want this to be:
+  #   enable_nacl = !is_ios && !is_android
+  enable_nacl = (is_linux && !is_chromeos && current_cpu == "x64") || is_nacl
+  enable_nacl_untrusted = enable_nacl
+  enable_pnacl = enable_nacl_untrusted
+
+  # If debug_devtools is set to true, JavaScript files for DevTools are stored
+  # as is and loaded from disk. Otherwise, a concatenated file is stored in
+  # resources.pak. It is still possible to load JS files from disk by passing
+  # --debug-devtools cmdline switch.
+  debug_devtools = false
+
+  # Enables WebRTC.
+  # TODO(GYP) make mac and android work.
+  enable_webrtc = !is_ios && !is_mac && !is_android
+
+  # Enables the Media Router.
+  enable_media_router = !is_ios && !is_android
+
+  # Enables proprietary codecs and demuxers; e.g. H264, MOV, AAC, and MP3.
+  # Android OS includes support for proprietary codecs regardless of building
+  # Chromium or Google Chrome. We also ship Google Chrome and Chromecast with
+  # proprietary codecs.
+  # TODO(GYP) The GYP build has || chromecast==1 for this:
+  proprietary_codecs = is_android || is_chrome_branded
+
+  enable_configuration_policy = true
+
+  # Enables support for background apps.
+  enable_background = !is_ios && !is_android
+
+  enable_captive_portal_detection = !is_android && !is_ios
+
+  # Enables use of the session service, which is enabled by default.
+  # Android stores them separately on the Java side.
+  enable_session_service = !is_android && !is_ios
+
+  enable_plugin_installation = is_win || is_mac
+
+  enable_app_list = !is_ios && !is_android
+
+  enable_supervised_users = !is_ios
+
+  enable_autofill_dialog = !is_ios
+
+  enable_google_now = !is_ios && !is_android
+
+  enable_one_click_signin = is_win || is_mac || (is_linux && !is_chromeos)
+
+  enable_remoting = !is_ios && !is_android
+
+  # Enable hole punching for the protected video.
+  enable_video_hole = is_android
+
+  # Enables browser side Content Decryption Modules. Required for embedders
+  # (e.g. Android and ChromeCast) that use a browser side CDM.
+  enable_browser_cdms = is_android
+
+  # Variable safe_browsing is used to control the build time configuration
+  # for safe browsing feature. Safe browsing can be compiled in 4 different
+  # levels: 0 disables it, 1 enables it fully, and 2 enables only UI and
+  # reporting features for use with Data Saver on Mobile, and 3 enables
+  # extended mobile protection via an external API.  When 3 is fully deployed,
+  # it will replace 2.
+  if (is_android) {
+    safe_browsing_mode = 2
+  } else if (is_ios) {
+    safe_browsing_mode = 0
+  } else {
+    safe_browsing_mode = 1
+  }
+}
+
+# Additional dependent variables -----------------------------------------------
+
+# Set the version of CLD.
+#   0: Don't specify the version. This option is for the Finch testing.
+#   1: Use only CLD1.
+#   2: Use only CLD2.
+if (is_android) {
+  cld_version = 1
+} else {
+  cld_version = 2
+}
+
+# libudev usage. This currently only affects the content layer.
+use_udev = is_linux
+
+# Enable the spell checker.
+enable_spellcheck = !is_android
+
+# Use the operating system's spellchecker rather than hunspell.
+use_platform_spellchecker = is_android || is_mac
+
+enable_pepper_cdms = enable_plugins && (is_linux || is_mac || is_win)
+
+# Enable basic printing support and UI.
+enable_basic_printing = !is_chromeos
+
+# Enable printing with print preview. It does not imply
+# enable_basic_printing. It's possible to build Chrome with preview only.
+enable_print_preview = !is_android
+
+# The seccomp-bpf sandbox is only supported on three architectures
+# currently.
+# Do not disable seccomp_bpf anywhere without talking to
+# security@chromium.org!
+use_seccomp_bpf = (is_linux || is_android) &&
+                  (current_cpu == "x86" || current_cpu == "x64" ||
+                   current_cpu == "arm" || current_cpu == "mipsel")
+
+# Enable notifications everywhere except iOS.
+enable_notifications = !is_ios
+
+# TODO(brettw) this should be moved to net and only dependents get this define.
+disable_ftp_support = is_ios
+
+enable_web_speech = !is_android && !is_ios
+
+use_dbus = is_linux
+
+enable_extensions = !is_android && !is_ios
+
+enable_task_manager = !is_ios && !is_android
+
+use_cups = is_desktop_linux || is_mac
+
+enable_themes = !is_android && !is_ios
+
+# TODO(scottmg) remove this when we've fixed printing.
+win_pdf_metafile_for_printing = true
+
+# Whether we are using the rlz library or not.  Platforms like Android send
+# rlz codes for searches but do not use the library.
+enable_rlz_support = is_win || is_mac || is_ios || is_chromeos
+enable_rlz = is_chrome_branded && enable_rlz_support
+
+enable_settings_app = enable_app_list && !is_chromeos
+
+enable_service_discovery = enable_mdns || is_mac
+
+enable_wifi_bootstrapping = is_win || is_mac
+
+# Image loader extension is enabled on ChromeOS only.
+enable_image_loader_extension = is_chromeos
+
+# Chrome OS: whether to also build the upcoming version of
+# ChromeVox, which can then be enabled via a command-line switch.
+enable_chromevox_next = false
+
+# Use brlapi from brltty for braille display support.
+use_brlapi = is_chromeos
+
+# Option controlling the use of GConf (the classic GNOME configuration
+# system).
+# TODO(GYP) also require !embedded to enable.
+use_gconf = is_linux && !is_chromeos
+
+# Hangout services is an extension that adds extra features to Hangouts.
+# For official GYP builds, this flag is set, it will likely need to be
+# parameterized in the future for a similar use.
+enable_hangout_services_extension = false
+
+# Whether to back up data before sync.
+enable_pre_sync_backup = is_win || is_mac || (is_linux && !is_chromeos)
+
+# WebVR support disabled until platform implementations have been added
+enable_webvr = false