Handle spaces in the name of the mini_installer.

chrome/installer/mini_installer/mini_installer.h

 // Copyright 2017 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 CHROME_INSTALLER_MINI_INSTALLER_MINI_INSTALLER_H_
 #define CHROME_INSTALLER_MINI_INSTALLER_MINI_INSTALLER_H_
 
 #include <windows.h>
 
 #include "chrome/installer/mini_installer/exit_code.h"
+#include "chrome/installer/mini_installer/mini_string.h"
 
 namespace mini_installer {
 
 // A container of a process exit code (eventually passed to ExitProcess) and
 // a Windows error code for cases where the exit code is non-zero.
 struct ProcessExitResult {
   DWORD exit_code;
   DWORD windows_error;
 
   explicit ProcessExitResult(DWORD exit) : exit_code(exit), windows_error(0) {}
   ProcessExitResult(DWORD exit, DWORD win)
       : exit_code(exit), windows_error(win) {}
 
   bool IsSuccess() const { return exit_code == SUCCESS_EXIT_CODE; }
 };
 
+// A stack-based string large enough to hold an executable to run
+// (which is a path), two additional path arguments, plus a few extra
+// arguments. Figure that MAX_PATH (260) is sufficient breathing room for the
+// extra arguments.
+using CommandString = StackString<MAX_PATH * 4>;
+
+// Appends everything following the path to the executable in |command_line|
+// verbatim to |buffer|, including all whitespace, quoted arguments,
+// etc. |buffer| is unchanged in case of error.
+void AppendCommandLineFlags(const wchar_t* command_line, CommandString* buffer);
+
 // Main function for Chrome's mini_installer. First gets a working dir, unpacks
 // the resources, and finally executes setup.exe to do the install/update. Also
 // handles invoking a previous version's setup.exe to patch itself in the case
 // of differential updates.
 ProcessExitResult WMain(HMODULE module);
 
 }  // namespace mini_installer
 
 #endif  // CHROME_INSTALLER_MINI_INSTALLER_MINI_INSTALLER_H_