Work on Mac GN build

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.
 
 # =============================================================================
 # BUILD FLAGS
 # =============================================================================
 #
 # This block lists input arguments to the build, along with their default
 # values. GN requires listing them explicitly so it can validate input and have
@@ skipping 24 matching lines @@
 
   # Forces a 64-bit build on Windows. Does nothing on other platforms. Normally
   # we build 32-bit on Windows regardless of the current host OS bit depth.
   # Setting this flag will override this logic and generate 64-bit toolchains.
   #
   # Normally this would get set automatically when you specify a target using
   # the 64-bit toolchain. You can also set this on the command line to convert
   # the default toolchain to 64-bit.
   force_win64 = false
 
-  # Set to true on the command line when invoked by GYP. Build files can key
-  # off of this to make any GYP-output-specific changes to the build.
-  is_gyp = false
-
   # Selects the desired build flavor. Official builds get additional
   # processing to prepare for release. Normally you will want to develop and
   # test with this flag off.
   is_official_build = false
 
   # Select the desired branding flavor. False means normal Chromium branding,
   # true means official Google Chrome branding (requires extra Google-internal
   # resources).
   is_chrome_branded = false
 
   # 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
-
-  # When running in gyp-generating mode, this is the root of the build tree.
-  gyp_output_dir = "out"
-
-  # When running in gyp-generating mode, this flag indicates if the current GYP
-  # generator is xcode. Can only be true when building for iOS).
-  is_gyp_xcode_generator = false
 }
 
 # =============================================================================
 # 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.
@@ skipping 271 matching lines @@
   native_compiler_configs += [ "//build/config/mac:sdk", ]
 } else if (is_ios) {
   native_compiler_configs += [ "//build/config/ios:sdk", ]
 } else if (is_android) {
   native_compiler_configs += [ "//build/config/android:sdk", ]
 }
 if (!is_win) {
   native_compiler_configs += [ "//build/config/gcc:symbol_visibility_hidden" ]
 }
 if (is_clang) {
-  native_compiler_configs += [ "//build/config/clang:find_bad_constructs" ]
+  native_compiler_configs += [
+    "//build/config/clang:find_bad_constructs",
+    "//build/config/clang:extra_warnings",
+  ]
 }
 
 # Optimizations and debug checking.
 if (is_debug) {
   native_compiler_configs += [ "//build/config:debug" ]
   default_optimization_config = "//build/config/compiler:no_optimize"
 } else {
   native_compiler_configs += [ "//build/config:release" ]
   default_optimization_config = "//build/config/compiler:optimize"
 }
@@ skipping 99 matching lines @@
 } else if (is_linux) {
   host_toolchain = "//build/toolchain/linux:$build_cpu_arch"
   set_default_toolchain("//build/toolchain/linux:$cpu_arch")
 } else if (is_mac) {
   host_toolchain = "//build/toolchain/mac:clang"
   set_default_toolchain(host_toolchain)
 } else if (is_ios) {
   host_toolchain = "//build/toolchain/mac:host_clang"
   set_default_toolchain("//build/toolchain/mac:clang")
 }