headless: Add gn settings for embedded build and headless mode

build/config/features.gni

Index: build/config/features.gni
diff --git a/build/config/features.gni b/build/config/features.gni
index 16c4d3f88d5f7c08bad4f5a64f215af2065357eb..e04622c0e80a72b961b5a3d83326226009d76baa 100644
--- a/build/config/features.gni
+++ b/build/config/features.gni
@@ -16,6 +16,7 @@
 
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
+import("//build/config/headless_build.gni")
 if (is_android) {
   import("//build/config/android/config.gni")
 }
@@ -86,7 +87,7 @@ declare_args() {
 
   enable_one_click_signin = is_win || is_mac || (is_linux && !is_chromeos)
 
-  enable_remoting = !is_ios && !is_android && !is_chromecast
+  enable_remoting = !is_ios && !is_android && !is_chromecast && !is_headless
 
   # Enable hole punching for the protected video.
   enable_video_hole = is_android
@@ -125,7 +126,7 @@ declare_args() {
 cld_version = 2
 
 # libudev usage. This currently only affects the content layer.
-use_udev = is_linux && !is_chromecast
+use_udev = is_linux && !is_chromecast && !is_headless
 
 # Enable the spell checker.
 enable_spellcheck = !is_ios
@@ -134,11 +135,12 @@ enable_spellcheck = !is_ios
 use_browser_spellchecker = is_android || is_mac
 
 # Enable basic printing support and UI.
-enable_basic_printing = !is_chromeos && !is_chromecast && !is_ios
+enable_basic_printing =
+    !is_chromeos && !is_chromecast && !is_ios && !is_headless
 
 # 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
+enable_print_preview = !is_android && !is_chromecast && !is_ios && !is_headless
 
 # Enables the use of CDMs in pepper plugins.
 enable_pepper_cdms =
@@ -157,13 +159,13 @@ enable_notifications = !is_ios
 
 enable_web_speech = !is_android && !is_ios
 
-use_dbus = is_linux && !is_chromecast
+use_dbus = is_linux && !is_chromecast && !is_headless
 
 enable_extensions = !is_android && !is_ios
 
 enable_task_manager = !is_ios && !is_android
 
-use_cups = (is_desktop_linux || is_mac) && !is_chromecast
+use_cups = (is_desktop_linux || is_mac) && !is_chromecast && !is_headless
 
 enable_themes = !is_android && !is_ios
 
@@ -191,7 +193,7 @@ use_brlapi = is_chromeos
 
 # Option controlling the use of GConf (the classic GNOME configuration
 # system).
-use_gconf = is_linux && !is_chromeos && !is_chromecast
+use_gconf = is_linux && !is_chromeos && !is_chromecast && !is_headless
 
 # Whether to back up data before sync.
 enable_pre_sync_backup = is_win || is_mac || (is_linux && !is_chromeos)
@@ -199,3 +201,5 @@ enable_pre_sync_backup = is_win || is_mac || (is_linux && !is_chromeos)
 # Enable WebVR support by default on Android
 # Still requires command line flag to access API
 enable_webvr = is_android
+
+use_gio = is_desktop_linux && !is_headless