Work on GN iOS build.

tools/gn/gyp_target_writer.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/gyp_target_writer.h"
 
 #include <iostream>
 
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "tools/gn/build_settings.h"
 #include "tools/gn/builder_record.h"
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/gyp_binary_target_writer.h"
 #include "tools/gn/gyp_script_target_writer.h"
 #include "tools/gn/scheduler.h"
 #include "tools/gn/settings.h"
 #include "tools/gn/target.h"
 #include "tools/gn/toolchain.h"
 
+GypTargetWriter::TargetGroup::TargetGroup()
+    : debug(NULL),
+      release(NULL),
+      host_debug(NULL),
+      host_release(NULL),
+      debug64(NULL),
+      release64(NULL),
+      xcode_debug(NULL),
+      xcode_release(NULL),
+      xcode_host_debug(NULL),
+      xcode_host_release(NULL) {
+}
+
 GypTargetWriter::GypTargetWriter(const Target* target,
                                  const Toolchain* toolchain,
                                  const SourceDir& gyp_dir,
                                  std::ostream& out)
     : settings_(target->settings()),
       target_(target),
       toolchain_(toolchain),
       gyp_dir_(gyp_dir),
       out_(out),
       // All GYP paths are relative to GYP file.
@@ skipping 68 matching lines @@
 
 // static
 std::ostream& GypTargetWriter::Indent(std::ostream& out, int spaces) {
   const char kSpaces[81] =
       "                                        "
       "                                        ";
   CHECK(static_cast<size_t>(spaces) <= arraysize(kSpaces) - 1);
   out.write(kSpaces, spaces);
   return out;
 }