Return Windows error code when create-process fails.

chrome/installer/mini_installer/configuration.h

 // Copyright (c) 2012 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_CONFIGURATION_H_
 #define CHROME_INSTALLER_MINI_INSTALLER_CONFIGURATION_H_
 
 #include <windows.h>
 
+#include "chrome/installer/mini_installer/mini_string.h"
+
 namespace mini_installer {
 
 // A simple container of the mini_installer's configuration, as dictated by the
 // command line used to invoke it.
 class Configuration {
  public:
   enum Operation {
     INSTALL_PRODUCT,
     CLEANUP,
   };
@@ skipping 27 matching lines @@
 
   // Returns true if --chrome-frame is on the command line.
   bool has_chrome_frame() const { return has_chrome_frame_; }
 
   // Returns true if --multi-install is on the command line.
   bool is_multi_install() const { return is_multi_install_; }
 
   // Returns true if --system-level is on the command line.
   bool is_system_level() const { return is_system_level_; }
 
+  // Retuns true if --chrome-sxs is on the command line.
+  bool is_side_by_side() const { return is_side_by_side_; }
+
   // Returns the previous version contained in the image's resource.
   const wchar_t* previous_version() const { return previous_version_; }
 
  protected:
   void Clear();
   bool ParseCommandLine(const wchar_t* command_line);
   void ReadResources(HMODULE module);
 
   wchar_t** args_;
   const wchar_t* chrome_app_guid_;
   const wchar_t* command_line_;
   int argument_count_;
   Operation operation_;
   bool has_chrome_;
   bool has_chrome_frame_;
   bool is_multi_install_;
   bool is_system_level_;
+  bool is_side_by_side_;
   const wchar_t* previous_version_;
 
+ protected:
+  typedef StackString<128> ValueString;
+
+  // Virtual for testing.
+  virtual bool ReadClientStateRegistryValue(
+      const HKEY root_key, const wchar_t* app_guid,
+      LONG* retval, ValueString& value);
+
  private:
   Configuration(const Configuration&);
   Configuration& operator=(const Configuration&);
+
+  void SetChromeAppGuid();
 };
 
 }  // namespace mini_installer
 
 #endif  // CHROME_INSTALLER_MINI_INSTALLER_CONFIGURATION_H_