Rename is_chromeos in chrome/src.

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
 
+  # This indicates whether the chromeos interfaces and features should be
+  # made available.  Contrast with whether we are targetting the embedded
+  # OS.  That flag controls the linking, flags, filesystems, etc. we expect.
+  use_cros_fe = is_chromeos
+
   # 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 = (is_linux && !use_cros_fe && 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.
@@ skipping 25 matching lines @@
   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_one_click_signin = is_win || is_mac || (is_linux && !use_cros_fe)
 
   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
 
@@ skipping 40 matching lines @@
 # libudev usage. This currently only affects the content layer.
 use_udev = is_linux
 
 # Enable the spell checker.
 enable_spellcheck = !is_ios
 
 # Use the operating system's spellchecker rather than hunspell.
 use_browser_spellchecker = is_android || is_mac
 
 # Enable basic printing support and UI.
-enable_basic_printing = !is_chromeos
+enable_basic_printing = !use_cros_fe
 
 # 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) &&
@@ skipping 16 matching lines @@
 
 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_support = is_win || is_mac || is_ios || use_cros_fe
 enable_rlz = is_chrome_branded && enable_rlz_support
 
-enable_settings_app = enable_app_list && !is_chromeos
+enable_settings_app = enable_app_list && !use_cros_fe
 
 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
+enable_image_loader_extension = use_cros_fe
 
 # 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
+use_brlapi = use_cros_fe
 
 # Option controlling the use of GConf (the classic GNOME configuration
 # system).
 # TODO(GYP) also require !embedded to enable.
-use_gconf = is_linux && !is_chromeos
+use_gconf = is_linux && !use_cros_fe
 
 # Whether to back up data before sync.
-enable_pre_sync_backup = is_win || is_mac || (is_linux && !is_chromeos)
+enable_pre_sync_backup = is_win || is_mac || (is_linux && !use_cros_fe)
 
 # WebVR support disabled until platform implementations have been added
 enable_webvr = false
+
+#
+#  Maintain some sanity for refactoring build configs.
+#
+if (is_chromeos_os) {
+  assert(use_cros_fe, "ChromeOS targetting requires ChromeOS UI")
+}
+
+if (use_cros_fe) {
+  assert(!is_desktop_linux, "ChromeOS Frontend is not desktop linux")
+}
+
+assert(use_cros_fe == is_chromeos,
+       "is_chromeos and use_cros_fe are expected to be aliases, " +
+           "old and new, respectively")