Move printing defines to buildflag system.

build/config/features.gni

Index: build/config/features.gni
diff --git a/build/config/features.gni b/build/config/features.gni
index 304fafcd9139a3d327babe0194bf58a38a09b870..74c49608c78bc8d762dfb78a50a86f23f7a61fa6 100644
--- a/build/config/features.gni
+++ b/build/config/features.gni
@@ -76,8 +76,6 @@ declare_args() {
   # 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
@@ -93,13 +91,6 @@ declare_args() {
 
   use_gio = is_linux && !is_chromeos && !is_chromecast
 
-  # Enable basic printing support and UI.
-  enable_basic_printing = !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
-
   # Whether or not to use external popup menu.
   use_external_popup_menu = is_android || is_mac