Allow use_debug_fission to be passed to gcc_toolchain().

build/toolchain/gcc_toolchain.gni

 # 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/nacl/config.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/toolchain/cc_wrapper.gni")
 import("//build/toolchain/goma.gni")
 import("//build/toolchain/toolchain.gni")
 
@@ skipping 80 matching lines @@
 #  - is_component_build
 #      Whether to forcibly enable or disable component builds for this
 #      toolchain; if not specified, the toolchain will inherit the
 #      default setting.
 #  - is_nacl_glibc
 #      Whether NaCl code is built using Glibc instead of Newlib.
 #  - cc_wrapper
 #      Override the global cc_wrapper setting. e.g. "ccache" or "icecc".
 #      useful to opt-out of cc_wrapper in a particular toolchain by setting
 #      cc_wrapper = "" in it.
+#  - use_debug_fission
+#      Override the global use_debug_fission setting, useful if the particular
+#      toolchain should not be generating split-dwarf code.
 #  - use_goma
 #      Override the global use_goma setting, useful to opt-out of goma in a
 #      particular toolchain by setting use_gome = false in it.
 #  - use_gold
 #      Override the global use_gold setting, useful if the particular
 #      toolchain has a custom link step that is not actually using Gold.
 template("gcc_toolchain") {
   toolchain(target_name) {
     assert(defined(invoker.ar), "gcc_toolchain() must specify a \"ar\" value")
     assert(defined(invoker.cc), "gcc_toolchain() must specify a \"cc\" value")
@@ skipping 343 matching lines @@
       }
       if (defined(invoker.is_nacl_glibc)) {
         is_nacl_glibc = invoker.is_nacl_glibc
       }
       if (defined(invoker.symbol_level)) {
         symbol_level = invoker.symbol_level
       }
       if (defined(invoker.use_allocator)) {
         use_allocator = invoker.use_allocator
       }
+      if (defined(invoker.use_debug_fission)) {
+        use_debug_fission = invoker.use_debug_fission
+      }
       if (defined(invoker.use_gold)) {
         use_gold = invoker.use_gold
       }
       if (defined(invoker.use_sysroot)) {
         use_sysroot = invoker.use_sysroot
       }
 
       # Disable sanitizers for non-default toolchains.
       is_asan = false
       is_cfi = false
@@ skipping 39 matching lines @@
     ar = "${toolprefix}ar"
     nm = "${toolprefix}nm"
 
     forward_variables_from(invoker,
                            [
                              "toolchain_cpu",
                              "toolchain_os",
                              "use_gold",
                              "strip",
                            ])
+
+    if (defined(invoker.use_debug_fission)) {
+      use_debug_fission = invoker.use_debug_fission
+    }
   }
 }