Do not try to make Chrome default when registering it if it can't be made default unattended.

chrome/installer/setup/install.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.
 
 #include "chrome/installer/setup/install.h"
 
 #include <windows.h>
 #include <shlobj.h>
 #include <time.h>
-#include <winuser.h>
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
@@ skipping 120 matching lines @@
 void CopyPreferenceFileForFirstRun(const InstallerState& installer_state,
                                    const base::FilePath& prefs_source_path) {
   base::FilePath prefs_dest_path(installer_state.target_path().AppendASCII(
       installer::kDefaultMasterPrefs));
   if (!file_util::CopyFile(prefs_source_path, prefs_dest_path)) {
     VLOG(1) << "Failed to copy master preferences from:"
             << prefs_source_path.value() << " gle: " << ::GetLastError();
   }
 }
 
-// Returns true if the current process is running on the interactive window
-// station.  This cares not whether the input desktop is the default or not
-// (i.e., the screen saver is running, or what have you).
-bool IsInteractiveProcess() {
-  static const wchar_t kWinSta0[] = L"WinSta0";
-  HWINSTA window_station = ::GetProcessWindowStation();
-  if (window_station == NULL) {
-    PLOG(ERROR) << "Failed to get window station";
-    return false;
-  }
-
-  // Make the buffer one char longer and zero it to be certain it's terminated.
-  wchar_t name[arraysize(kWinSta0) + 1] = {};
-  DWORD buffer_length = sizeof(kWinSta0);
-  DWORD name_length = 0;
-  return (GetUserObjectInformation(window_station, UOI_NAME, &name[0],
-                                   buffer_length, &name_length) &&
-          name_length == buffer_length &&
-          lstrcmpi(kWinSta0, name) == 0);
-}
-
 // This function installs a new version of Chrome to the specified location.
 //
 // setup_path: Path to the executable (setup.exe) as it will be copied
 //           to Chrome install folder after install is complete
 // archive_path: Path to the archive (chrome.7z) as it will be copied
 //               to Chrome install folder after install is complete
 // src_path: the path that contains a complete and unpacked Chrome package
 //           to be installed.
 // temp_path: the path of working directory used during installation. This path
 //            does not need to exist.
@@ skipping 294 matching lines @@
   // error checking here because this operation will fail if user doesn't
   // have admin rights and we want to ignore the error.
   AddChromeToMediaPlayerList();
 
   // Make Chrome the default browser if desired when possible. Otherwise, only
   // register it with Windows.
   BrowserDistribution* dist = product.distribution();
   const string16 chrome_exe(
       installer_state.target_path().Append(installer::kChromeExe).value());
   VLOG(1) << "Registering Chrome as browser: " << chrome_exe;
-  if (make_chrome_default) {
-    if (ShellUtil::CanMakeChromeDefaultUnattended()) {
-      int level = ShellUtil::CURRENT_USER;
-      if (installer_state.system_install())
-        level = level | ShellUtil::SYSTEM_LEVEL;
-      ShellUtil::MakeChromeDefault(dist, level, chrome_exe, true);
-    } else if (IsInteractiveProcess()) {
-      ShellUtil::ShowMakeChromeDefaultSystemUI(dist, chrome_exe);
-    } else {
-      ShellUtil::RegisterChromeBrowser(dist, chrome_exe, string16(), false);
-    }
+  if (make_chrome_default && ShellUtil::CanMakeChromeDefaultUnattended()) {
+    int level = ShellUtil::CURRENT_USER;
+    if (installer_state.system_install())
+      level = level | ShellUtil::SYSTEM_LEVEL;
+    ShellUtil::MakeChromeDefault(dist, level, chrome_exe, true);
   } else {
     ShellUtil::RegisterChromeBrowser(dist, chrome_exe, string16(), false);
   }
 }
 
 InstallStatus InstallOrUpdateProduct(
     const InstallationState& original_state,
     const InstallerState& installer_state,
     const base::FilePath& setup_path,
     const base::FilePath& archive_path,
@@ skipping 201 matching lines @@
   if (app_host_path.empty())
     return false;
 
   CommandLine cmd(app_host_path);
   cmd.AppendSwitchASCII(::switches::kInstallFromWebstore, app_code);
   VLOG(1) << "App install command: " << cmd.GetCommandLineString();
   return base::LaunchProcess(cmd, base::LaunchOptions(), NULL);
 }
 
 }  // namespace installer