Apply arflags to dependent configs in GN.

tools/gn/config_values.cc

 // 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.
 
 #include "tools/gn/config_values.h"
 
 namespace {
 
 template<typename T>
 void VectorAppend(std::vector<T>* append_to,
                   const std::vector<T>& append_this) {
   if (append_this.empty())
     return;
   append_to->insert(append_to->end(),append_this.begin(), append_this.end());
 }
 
 }  // namespace
 
 ConfigValues::ConfigValues() {
 }
 
 ConfigValues::~ConfigValues() {
 }
 
 void ConfigValues::AppendValues(const ConfigValues& append) {
   VectorAppend(&asmflags_,     append.asmflags_);
+  VectorAppend(&arflags_,      append.arflags_);
   VectorAppend(&cflags_,       append.cflags_);
   VectorAppend(&cflags_c_,     append.cflags_c_);
   VectorAppend(&cflags_cc_,    append.cflags_cc_);
   VectorAppend(&cflags_objc_,  append.cflags_objc_);
   VectorAppend(&cflags_objcc_, append.cflags_objcc_);
   VectorAppend(&defines_,      append.defines_);
   VectorAppend(&include_dirs_, append.include_dirs_);
   VectorAppend(&ldflags_,      append.ldflags_);
   VectorAppend(&lib_dirs_,     append.lib_dirs_);
   VectorAppend(&libs_,         append.libs_);
 
   // Only append precompiled header if there isn't one. It might be nice to
   // throw an error if there are conflicting precompiled headers, but that
   // requires piping through some context of the actual configs involved, and
   // conflicts here should be very unusual. Instead, use the first value.
   if (!append.precompiled_header_.empty() && !precompiled_header_.empty())
     precompiled_header_ = append.precompiled_header_;
   if (!append.precompiled_source_.is_null() && !precompiled_source_.is_null())
     precompiled_source_ = append.precompiled_source_;
 }