Make unwind table inclusion configurable.

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")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/toolchain/ccache.gni")
 
@@ skipping 52 matching lines @@
   # value expression until after its input values such as use_gold have
   # been set, e.g. by a toolchain_args() block.
   use_debug_fission = "default"
 
   if (is_win) {
     # Whether the VS xtree header has been patched to disable warning 4702. If
     # it has, then we don't need to disable 4702 (unreachable code warning).
     # The patch is preapplied to the internal toolchain and hence all bots.
     msvs_xtree_patched = false
   }
+
+  # Omit unwind support in official builds to save space.
+  # We can use breakpad for these builds.
+  exclude_unwind_tables = is_chrome_branded && is_official_build
 }
 
 # Apply the default logic for these values if they were not set explicitly.
 if (gold_path == false) {
   if (use_gold) {
     gold_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
                             root_build_dir)
   } else {
     gold_path = ""
   }
@@ skipping 135 matching lines @@
     defines += [ "_FILE_OFFSET_BITS=64" ]
 
     if (!is_android) {
       defines += [
         "_LARGEFILE_SOURCE",
         "_LARGEFILE64_SOURCE",
       ]
     }
 
     if (!is_nacl) {
-      # Omit unwind support in official builds to save space.
-      # We can use breakpad for these builds.
-      if (is_chrome_branded && is_official_build) {
+      if (exclude_unwind_tables) {
         cflags += [
           "-fno-unwind-tables",
           "-fno-asynchronous-unwind-tables",
         ]
         defines += [ "NO_UNWIND_TABLES" ]
       } else {
         cflags += [ "-funwind-tables" ]
       }
     }
   }
@@ skipping 1055 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)
   }
 }