[GN] Add support for generating Xcode projects.

tools/gn/create_bundle_target_generator.cc

 // Copyright 2016 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/create_bundle_target_generator.h"
 
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/parse_tree.h"
 #include "tools/gn/scope.h"
 #include "tools/gn/substitution_type.h"
@@ skipping 23 matching lines @@
                     &bundle_data.resources_dir()))
     return;
   if (!GetBundleDir(bundle_data.root_dir(),
                     variables::kBundleExecutableDir,
                     &bundle_data.executable_dir()))
     return;
   if (!GetBundleDir(bundle_data.root_dir(),
                     variables::kBundlePlugInsDir,
                     &bundle_data.plugins_dir()))
     return;
+
+  const Value* value = scope_->GetValue(variables::kProductType, true);
+  if (value) {
+    if (!value->VerifyTypeIs(Value::STRING, err_))
+      return;
+
+    bundle_data.product_type().assign(value->string_value());
+  }
 }
 
 bool CreateBundleTargetGenerator::GetBundleDir(
     const SourceDir& bundle_root_dir,
     const base::StringPiece& name,
     SourceDir* bundle_dir) {
   const Value* value = scope_->GetValue(name, true);
   if (!value)
     return true;
   if (!value->VerifyTypeIs(Value::STRING, err_))
     return false;
   std::string str = value->string_value();
+  if (!str.empty() && str[str.size() - 1] != '/')

[sdefresne, 2016/04/27 17:41:53]

Without this "bundle_dir->SwapValue(&str);" causes a DCHECK because the BUILD.gn
files do not use trailing "/". Is it better to fix the BUILD.gn files or to fix
the code here? The DCHECK is pre-existing my CL (it was introduced by recent
change by rsesek).

+    str.push_back('/');
   if (!EnsureStringIsInOutputDir(GetBuildSettings()->build_dir(), str,
                                  value->origin(), err_))
     return false;
   if (str != bundle_root_dir.value() &&
       !IsStringInOutputDir(bundle_root_dir, str)) {
     *err_ = Err(value->origin(), "Path is not in bundle root dir.",
         "The given file should be in the bundle root directory or below.\n"
         "Normally you would do \"$bundle_root_dir/foo\". I interpreted this\n"
         "as \"" + str + "\".");
     return false;
   }
   bundle_dir->SwapValue(&str);
   return true;
 }