Fix generation of target in Xcode project when using output_name.

tools/gn/xcode_object.h

 // 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.
 
 #ifndef TOOLS_GN_XCODE_OBJECT_H_
 #define TOOLS_GN_XCODE_OBJECT_H_
 
 #include <iosfwd>
 #include <map>
 #include <memory>
@@ skipping 225 matching lines @@
 
 // PBXNativeTarget ------------------------------------------------------------
 
 class PBXNativeTarget : public PBXTarget {
  public:
   PBXNativeTarget(const std::string& name,
                   const std::string& shell_script,
                   const std::string& config_name,
                   const PBXAttributes& attributes,
                   const std::string& product_type,
+                  const std::string& product_name,
                   const PBXFileReference* product_reference);
   ~PBXNativeTarget() override;
 
   void AddFileForIndexing(const PBXFileReference* file_reference);
 
   // PBXObject implementation.
   PBXObjectClass Class() const override;
   void Print(std::ostream& out, unsigned indent) const override;
 
  private:
   const PBXFileReference* product_reference_;
   std::string product_type_;
+  std::string product_name_;
 
   DISALLOW_COPY_AND_ASSIGN(PBXNativeTarget);
 };
 
 // PBXProject -----------------------------------------------------------------
 
 class PBXProject : public PBXObject {
  public:
   PBXProject(const std::string& name,
              const std::string& config_name,
@@ skipping 115 matching lines @@
   void Print(std::ostream& out, unsigned indent) const override;
 
  private:
   std::vector<std::unique_ptr<XCBuildConfiguration>> configurations_;
   const PBXObject* owner_reference_;
 
   DISALLOW_COPY_AND_ASSIGN(XCConfigurationList);
 };
 
 #endif  // TOOLS_GN_XCODE_OBJECT_H_