Add GN files for chrome_elf

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")
 if (cpu_arch == "arm") {
   import("//build/config/arm.gni")
 }
 if (cpu_arch == "mipsel" || cpu_arch == "mips64el") {
   import("//build/config/mips.gni")
@@ skipping 880 matching lines @@
 #   configs += [ "//build/config/compiler/optimize_max" ]
 
 # Shared settings for both "optimize" and "optimize_max" configs.
 if (is_win) {
   common_optimize_on_cflags = [
     "/O2",
     "/Ob2",  # both explicit and auto inlining.
     "/Oy-",  # disable omitting frame pointers, must be after /o2.
     "/Os",  # favor size over speed.
   ]
-  common_optimize_on_ldflags = []
+  if (!is_asan) {
+    common_optimize_on_cflags += [
+      # Put data in separate COMDATs. This allows the linker
+      # to put bit-identical constants at the same address even if
+      # they're unrelated constants, which saves binary size.
+      # This optimization can't be used when ASan is enabled because
+      # it is not compatible with the ASan ODR checker.
+      "/Gw",
+    ]
+  }
+  common_optimize_on_ldflags = [ "/OPT:REF" ]
 } else {
   common_optimize_on_cflags = [
     # Don't emit the GCC version ident directives, they just end up in the
     # .comment section taking up binary size.
     "-fno-ident",
 
     # Put data and code in their own sections, so that unused symbols
     # can be removed at link time with --gc-sections.
     "-fdata-sections",
     "-ffunction-sections",
@@ skipping 123 matching lines @@
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }