Rename is_chromeos in chrome/src.

build/config/BUILDCONFIG.gn

 # Copyright (c) 2013 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.
 
 # =============================================================================
 # PLATFORM SELECTION
 # =============================================================================
 #
 # There are two main things to set: "os" and "cpu". The "toolchain" is the name
 # of the GN thing that encodes combinations of these things.
@@ skipping 107 matching lines @@
   #   0 means no symbols.
   #   -1 means auto-set (off in release, regular in debug).
   symbol_level = -1
 
   # Component build.
   is_component_build = false
 
   # Debug build.
   is_debug = true
 
+  # Whether we're building components and interfaces for ChromeOS
+  # This is for backwards compatability until the rename in complete in all
+  # dependent files.  See use_cros_fe in features.gni.  They should be the same.
+  # TODO(petermayo): Remove this when it doesn't break known compiles.
+  is_chromeos = current_os == "chromeos"
+
   # Whether we're a traditional desktop unix.
-  is_desktop_linux = current_os == "linux" && current_os != "chromeos"
+  is_desktop_linux = current_os == "linux" && !is_chromeos
 
   # Set to true when compiling with the Clang compiler. Typically this is used
   # to configure warnings.
   is_clang = current_os == "mac" || current_os == "ios" ||
              current_os == "linux" || current_os == "chromeos"
 
   # Compile for Address Sanitizer to find memory bugs.
   is_asan = false
 
   # Compile for Leak Sanitizer to find leaks.
   is_lsan = false
 
   # Compile for Memory Sanitizer to find uninitialized reads.
   is_msan = false
 
   # Compile for Thread Sanitizer to find threading bugs.
   is_tsan = false
 
   if (current_os == "chromeos") {
     # Allows the target toolchain to be injected as arguments. This is needed
     # to support the CrOS build system which supports per-build-configuration
     # toolchains.
     cros_use_custom_toolchain = false
+  } else {
+    cros_use_custom_toolchain = false
   }
 
   # DON'T ADD MORE FLAGS HERE. Read the comment above.
 }
 
 # =============================================================================
 # OS DEFINITIONS
 # =============================================================================
 #
 # We set these various is_FOO booleans for convenience in writing OS-based
 # conditions.
 #
-# - is_android, is_chromeos, is_ios, and is_win should be obvious.
+# - is_android, is_ios, and is_win should be obvious.
 # - is_mac is set only for desktop Mac. It is not set on iOS.
 # - is_posix is true for mac and any Unix-like system (basically everything
 #   except Windows).
 # - is_linux is true for desktop Linux and ChromeOS, but not Android (which is
 #   generally too different despite being based on the Linux kernel).
+# - is_chromeos_os is true if the results are expected to run on a ChromeOS
+#   machine, using the filesystem and runtime libraries specifed by
+#   a build of that OS, rather than local linux.  E.g. presume an update
+#   system, journalled files system, storage modes, no other apps, etc.
 #
 # Do not add more is_* variants here for random lesser-used Unix systems like
 # aix or one of the BSDs. If you need to check these, just check the
 # current_os value directly.
 
 if (current_os == "win" || current_os == "winrt_81" ||
     current_os == "winrt_81_phone" || current_os == "winrt_10") {
   is_android = false
-  is_chromeos = false
+  is_chromeos_os = false
   is_ios = false
   is_linux = false
   is_mac = false
   is_nacl = false
   is_posix = false
   is_win = true
 } else if (current_os == "mac") {
   is_android = false
-  is_chromeos = false
+  is_chromeos_os = false
   is_ios = false
   is_linux = false
   is_mac = true
   is_nacl = false
   is_posix = true
   is_win = false
 } else if (current_os == "android") {
   is_android = true
-  is_chromeos = false
+  is_chromeos_os = false
   is_ios = false
   is_linux = false
   is_mac = false
   is_nacl = false
   is_posix = true
   is_win = false
 } else if (current_os == "chromeos") {
   is_android = false
-  is_chromeos = true
+  assert(is_chromeos, "ChromiumOS requires is_chromeos.")
+  is_chromeos_os = true
   is_ios = false
   is_linux = true
   is_mac = false
   is_nacl = false
   is_posix = true
   is_win = false
 } else if (current_os == "nacl") {
   # current_os == "nacl" will be passed by the nacl toolchain definition.
   # It is not set by default or on the command line. We treat is as a
   # Posix variant.
   is_android = false
-  is_chromeos = false
+  is_chromeos_os = false
   is_ios = false
   is_linux = false
   is_mac = false
   is_nacl = true
   is_posix = true
   is_win = false
 } else if (current_os == "ios") {
   is_android = false
-  is_chromeos = false
+  is_chromeos_os = false
   is_ios = true
   is_linux = false
   is_mac = false
   is_nacl = false
   is_posix = true
   is_win = false
 } else if (current_os == "linux") {
   is_android = false
-  is_chromeos = false
+  is_chromeos_os = false
   is_ios = false
   is_linux = true
   is_mac = false
   is_nacl = false
   is_posix = true
   is_win = false
 }
 
 # =============================================================================
 # SOURCES FILTERS
@@ skipping 74 matching lines @@
 }
 if (!is_android) {
   sources_assignment_filter += [
     "*_android.h",
     "*_android.cc",
     "*_android_unittest.h",
     "*_android_unittest.cc",
     "*\bandroid/*",
   ]
 }
+
+#TODO(petermayo): Move this to features.gni with the removal of is_chromeos
 if (!is_chromeos) {
   sources_assignment_filter += [
     "*_chromeos.h",
     "*_chromeos.cc",
     "*_chromeos_unittest.h",
     "*_chromeos_unittest.cc",
     "*\bchromeos/*",
   ]
 }
 
@@ skipping 277 matching lines @@
     forward_variables_from(invoker, "*")
 
     # All shared libraries must have the sanitizer deps to properly link in
     # asan mode (this target will be empty in other cases).
     if (!defined(deps)) {
       deps = []
     }
     deps += [ "//build/config/sanitizers:deps" ]
   }
 }