GN: Use std::unique_ptr for owned pointers in VisualStudioWriter.

tools/gn/visual_studio_writer.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_VISUAL_STUDIO_WRITER_H_
 #define TOOLS_GN_VISUAL_STUDIO_WRITER_H_
 
 #include <iosfwd>
+#include <memory>
 #include <string>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "tools/gn/path_output.h"
 
 namespace base {
 class FilePath;
 }
@@ skipping 51 matching lines @@
                     const std::string& label_dir_path,
                     const std::string& config_platform);
     ~SolutionProject() override;
 
     // Absolute label dir path.
     std::string label_dir_path;
     // Configuration platform. May be different than solution config platform.
     std::string config_platform;
   };
 
-  using SolutionProjects = std::vector<SolutionProject*>;
-  using SolutionFolders = std::vector<SolutionEntry*>;
+  using SolutionProjects = std::vector<std::unique_ptr<SolutionProject>>;
+  using SolutionFolders = std::vector<std::unique_ptr<SolutionEntry>>;
 
   VisualStudioWriter(const BuildSettings* build_settings,
                      const char* config_platform,
                      Version version);
   ~VisualStudioWriter();
 
   bool WriteProjectFiles(const Target* target, Err* err);
   bool WriteProjectFileContents(std::ostream& out,
                                 const SolutionProject& solution_project,
                                 const Target* target,
@@ skipping 36 matching lines @@
   // Semicolon-separated Windows SDK include directories.
   std::string windows_kits_include_dirs_;
 
   // Path formatter for ninja targets.
   PathOutput ninja_path_output_;
 
   DISALLOW_COPY_AND_ASSIGN(VisualStudioWriter);
 };
 
 #endif  // TOOLS_GN_VISUAL_STUDIO_WRITER_H_