Beginning work on GN build

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")
+import("//build/config/chromecast_build.gni")
+if (is_android) {
+  import("//build/config/android/config.gni")
+}
+
+declare_args() {
+  # Multicast DNS.
+  enable_mdns = is_win || is_linux
+
+  enable_extensions = !is_android && !is_ios
+  enable_plugins = (!is_android && !is_ios) || is_chromecast
+  enable_pdf = !is_android && !is_ios && !is_chromecast
+
+  # Enables Native Client support.
+  # TODO(mcgrathr): When mipsel-nacl-clang is available, drop the exclusion.
+  enable_nacl =
+      !is_ios && !is_android && !is_chromecast && current_cpu != "mipsel"
+
+  # 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.
+  enable_webrtc = !is_ios
+
+  # Enables the Media Router.
+  enable_media_router = !is_ios
+
+  # Enables proprietary codecs and demuxers; e.g. H264, AAC, MP3, and MP4.
+  # We always build Google Chrome and Chromecast with proprietary codecs.
+  proprietary_codecs = is_chrome_branded || is_chromecast
+
+  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_chromeos
+
+  enable_supervised_users = !is_ios
+
+  enable_remoting = !is_ios && !is_chromecast
+
+  # 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 || is_chromecast
+
+  # Hangout services is an extension that adds extra features to Hangouts.
+  # For official GYP builds, this flag is set.
+  enable_hangout_services_extension = false
+
+  # Variable safe_browsing is used to control the build time configuration for
+  # safe browsing feature. Safe browsing can be compiled in 3 different levels:
+  # 0 disables it, 1 enables it fully, and 2 enables mobile protection via an
+  # external API.
+  if (is_android) {
+    safe_browsing_mode = 2
+  } else if (is_ios) {
+    safe_browsing_mode = 0
+  } else {
+    safe_browsing_mode = 1
+  }
+
+  # Set to true make a build that disables activation of field trial tests
+  # specified in testing/variations/fieldtrial_testing_config_*.json.
+  # Note: this setting is ignored if is_chrome_branded.
+  fieldtrial_testing_like_official_build = is_chrome_branded
+
+  use_cups = (is_desktop_linux || is_mac) && !is_chromecast
+
+  # Enables Wi-Fi Display functionality
+  # WARNING: This enables MPEG Transport Stream (MPEG-TS) encoding!
+  enable_wifi_display = false
+
+  # libudev usage. This currently only affects the content layer.
+  use_udev = is_linux && !is_chromecast
+
+  use_dbus = is_linux && !is_chromecast
+
+  # Option controlling the use of GConf (the classic GNOME configuration
+  # system).
+  use_gconf = is_linux && !is_chromeos && !is_chromecast
+
+  use_gio = is_linux && !is_chromeos && !is_chromecast
+
+  # Enable basic printing support and UI.
+  enable_basic_printing = !is_chromeos && !is_chromecast && !is_ios
+
+  # 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 && !is_chromecast && !is_ios
+}
+
+# Additional dependent variables -----------------------------------------------
+
+# Enable the spell checker.
+enable_spellcheck = !is_ios
+
+# Use the operating system's spellchecker rather than hunspell.
+use_browser_spellchecker = is_android || is_mac
+
+# Enables the use of CDMs in pepper plugins.
+enable_pepper_cdms =
+    enable_plugins && (is_linux || is_mac || is_win) && !is_chromecast
+
+# The seccomp-bpf sandbox is only supported on five 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 == "arm64" || current_cpu == "mipsel")
+
+# Enable notifications everywhere except iOS.
+enable_notifications = !is_ios
+
+enable_web_speech = !is_android && !is_ios
+
+enable_task_manager = !is_ios && !is_android
+
+enable_themes = !is_android && !is_ios
+
+# 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
+
+# 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
+
+# Enable WebVR support by default on Android
+# Still requires command line flag to access API
+enable_webvr = is_android
+
+enable_configuration_policy = !is_ios
+
+enable_mac_keystone = is_mac && is_chrome_branded && is_official_build
+enable_mac_crash_collection = is_mac && is_chrome_branded && is_official_build