Experimentally isolate GetOpenFileName in a utility process.

ui/base/win/open_file_name_win.h

 // Copyright (c) 2014 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 UI_BASE_WIN_OPEN_FILE_NAME_WIN_H_
 #define UI_BASE_WIN_OPEN_FILE_NAME_WIN_H_
 
 #include <Windows.h>
 #include <Commdlg.h>
 
@@ skipping 14 matching lines @@
 // Encapsulates an OPENFILENAME struct and related buffers. Also provides static
 // methods for interpreting the properties of an OPENFILENAME.
 class UI_BASE_EXPORT OpenFileName {
  public:
   // Initializes the OPENFILENAME, which may be accessed using Get(). All fields
   // will be NULL except for |lStructSize|, |lpstrFile|, and |nMaxFile|. The
   // file buffer will initially contain a null-terminated empty string.
   OpenFileName(HWND parent_window, DWORD flags);
   ~OpenFileName();
 
+  // Initializes |lpstrFilter| from the label/pattern pairs in |filters|.
+  void SetFilters(
+      const std::vector<Tuple2<base::string16, base::string16> >& filters);
+
   // Sets |lpstrInitialDir| and |lpstrFile|.
   void SetInitialSelection(const base::FilePath& initial_directory,
                            const base::FilePath& initial_filename);
 
   // Returns the single selected file, or an empty path if there are more or
   // less than one results.
   base::FilePath GetSingleResult();
 
   // Returns the selected file or files.
   void GetResult(base::FilePath* directory,
                  std::vector<base::FilePath>* filenames);
 
   // Returns the OPENFILENAME structure.
   OPENFILENAME* GetOPENFILENAME() { return &openfilename_; }
 
+  // Returns the OPENFILENAME structure.
+  const OPENFILENAME* GetOPENFILENAME() const { return &openfilename_; }
+
+  // Stores directory and filenames in the buffer pointed to by
+  // |openfilename->lpstrFile| and sized |openfilename->nMaxFile|.
+  static void SetResult(const base::FilePath& directory,
+                        const std::vector<base::FilePath>& filenames,
+                        OPENFILENAME* openfilename);
+
+  // Returns a vector of label/pattern pairs built from
+  // |openfilename->lpstrFilter|.
+  static std::vector<Tuple2<base::string16, base::string16> > GetFilters(
+      const OPENFILENAME* openfilename);
+
  private:
   OPENFILENAME openfilename_;
   base::string16 initial_directory_buffer_;
   wchar_t filename_buffer_[UNICODE_STRING_MAX_CHARS];
+  base::string16 filter_buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(OpenFileName);
 };
 
 }  // namespace win
 }  // namespace ui
 
 #endif  // UI_BASE_WIN_OPEN_FILE_NAME_WIN_H_