Do not write magic string to registry for non Google Chrome builds.

chrome/installer/mini_installer/mini_installer.cc

 // Copyright (c) 2006-2009 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.
 
 // mini_installer.exe is the first exe that is run when chrome is being
 // installed or upgraded. It is designed to be extremely small (~5KB with no
 // extra resources linked) and it has two main jobs:
 //   1) unpack the resources (possibly decompressing some)
 //   2) run the real installer (setup.exe) with appropiate flags.
 //
@@ skipping 487 matching lines @@
 }
 
 // Main function. First gets a working dir, unpacks the resources and finally
 // executes setup.exe to do the install/upgrade.
 int WMain(HMODULE module) {
   // First get a path where we can extract payload
   wchar_t base_path[MAX_PATH];
   if (!GetWorkDir(module, base_path))
     return 101;
 
+#if defined(GOOGLE_CHROME_BUILD)
   // Set the magic suffix in registry to try full installer next time. We ignore
   // any errors here and we try to set the suffix for user level as well as
-  // system level.
+  // system level. This only applies to Google Chrome distribution.
   SetFullInstallerFlag(HKEY_LOCAL_MACHINE);
   SetFullInstallerFlag(HKEY_CURRENT_USER);
+#endif
 
   wchar_t archive_path[MAX_PATH] = {0};
   wchar_t setup_path[MAX_PATH] = {0};
   if (!UnpackBinaryResources(module, base_path, archive_path, MAX_PATH,
                              setup_path, MAX_PATH))
     return 102;
 
   int exit_code = 103;
   if (!RunSetup(archive_path, setup_path, &exit_code))
     return exit_code;
 
   wchar_t value[4];
   if ((!ReadValueFromRegistry(HKEY_CURRENT_USER, kCleanupRegistryKey,
                               kCleanupRegistryValueName, value, 4)) ||
       (value[0] != L'0'))
     DeleteExtractedFiles(base_path, archive_path, setup_path);
 
   return exit_code;
 }
 }  // namespace mini_installer
 
 
 int MainEntryPoint() {
   int result = mini_installer::WMain(::GetModuleHandle(NULL));
   ::ExitProcess(result);
 }