[Fixit-Dec-2012] Auto-launch system-level Chrome post user-level Chrome self-destruction.

chrome/installer/util/install_util.cc

 // 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.
 //
 // See the corresponding header file for description of the functions in this
 // file.
 
 #include "chrome/installer/util/install_util.h"
 
 #include <shellapi.h>
@@ skipping 366 matching lines @@
 }
 
 bool InstallUtil::GetSentinelFilePath(const FilePath::CharType* file,
                                       BrowserDistribution* dist,
                                       FilePath* path) {
   FilePath exe_path;
   if (!PathService::Get(base::DIR_EXE, &exe_path))
     return false;
 
   if (IsPerUserInstall(exe_path.value().c_str())) {
-    *path = exe_path;
+    const FilePath maybe_product_dir(exe_path.DirName().DirName());
+    if (file_util::PathExists(exe_path.Append(installer::kChromeExe))) {
+      // DIR_EXE is most likely Chrome's directory in which case |exe_path| is
+      // the user-level sentinel path.
+      *path = exe_path;
+    } else if (file_util::PathExists(
+                   maybe_product_dir.Append(installer::kChromeExe))) {
+      // DIR_EXE can also be the Installer directory if this is called from a
+      // setup.exe running from Application\<version>\Installer (see
+      // InstallerState::GetInstallerDirectory) in which case Chrome's directory
+      // is two levels up.
+      *path = maybe_product_dir;
+    } else {
+      NOTREACHED();
+      return false;
+    }
   } else {
     std::vector<FilePath> user_data_dir_paths;
     installer::GetChromeUserDataPaths(dist, &user_data_dir_paths);
 
     if (!user_data_dir_paths.empty())
       *path = user_data_dir_paths[0];
     else
       return false;
   }
 
@@ skipping 183 matching lines @@
   // Open the program and see if it references the expected file.
   base::win::ScopedHandle handle;
   BY_HANDLE_FILE_INFORMATION info = {};
 
   return (OpenForInfo(program, &handle) &&
           GetInfo(handle, &info) &&
           info.dwVolumeSerialNumber == file_info_.dwVolumeSerialNumber &&
           info.nFileIndexHigh == file_info_.nFileIndexHigh &&
           info.nFileIndexLow == file_info_.nFileIndexLow);
 }