Remove Chrome OS-related GN build configuration

build/config/compiler/BUILD.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.
 
 import("//build/config/android/config.gni")
 import("//build/config/chrome_build.gni")
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }
 if (current_cpu == "mipsel" || current_cpu == "mips64el") {
@@ skipping 86 matching lines @@
   if (is_mac) {
     cflags += [ "-fstack-protector-all" ]
   } else if (is_linux) {
     cflags += [
       "-fstack-protector",
       "--param=ssp-buffer-size=4",
     ]
   }
 
   # Linker warnings.
-  if (!(is_chromeos && current_cpu == "arm") && !is_mac && !is_ios) {
-    # TODO(jochen): Enable this on chromeos on arm. http://crbug.com/356580
+  if (!is_mac && !is_ios) {
     ldflags += [ "-Wl,--fatal-warnings" ]
   }
 
   # Common options for AddressSanitizer, LeakSanitizer, ThreadSanitizer and
   # MemorySanitizer
   if (using_sanitizer) {
     cflags += [
       "-fno-omit-frame-pointer",
       "-gline-tables-only",
     ]
@@ skipping 300 matching lines @@
         # http://crbug.com/492177.  Turning it on saves over 12 MB of binary
         # size, but it seems to regress cold startup time by over a second
         # (see http://crbug.com/492809).
         # TODO(thakis): Check if disabling ICF would inmprove android cold start
         # times by several seconds too.
         ldflags += [ "-Wl,--icf=safe" ]
       } else {
         ldflags += [ "-Wl,--icf=all" ]
       }
     }
-
-    # TODO(thestig): Make this flag work with GN.
-    #if (!is_official_build && !is_chromeos && !(is_asan || is_lsan || is_tsan || is_msan)) {
-    #  ldflags += [
-    #    "-Wl,--detect-odr-violations",
-    #  ]
-    #}
   }
 
   if (linux_use_bundled_binutils) {
     binutils_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
                                 root_build_dir)
     cflags += [ "-B$binutils_path" ]
   }
 
   # Clang-specific compiler flags setup.
   # ------------------------------------
@@ skipping 681 matching lines @@
   if (symbol_level == 0) {
     configs = [ ":no_symbols" ]
   } else if (symbol_level == 1) {
     configs = [ ":minimal_symbols" ]
   } else if (symbol_level == 2) {
     configs = [ ":symbols" ]
   } else {
     assert(false)
   }
 }