If Chrome Binaries version > App Host version, then update App Host.

chrome/installer/launcher_support/chrome_launcher_support.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/launcher_support/chrome_launcher_support.h"
 
 #include <windows.h>
 #include <tchar.h>
+#include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
+#include "base/logging.h"
+#include "base/process_util.h"
 #ifndef OFFICIAL_BUILD
 #include "base/path_service.h"
 #endif
 #include "base/string16.h"
 #include "base/win/registry.h"
 
 namespace {
 
 // TODO(erikwright): These constants are duplicated all over the place.
 // Consolidate them somehow.
-const wchar_t kChromeRegClientStateKey[] =
+const wchar_t kChromeBinariesRegClientStateKey[] =
     L"Software\\Google\\Update\\ClientState\\"
-    L"{8A69D345-D564-463c-AFF1-A69D9E530F96}";
+    L"{4DC8B4CA-1BDA-483e-B5FA-D3C12E15B62D}";
+const wchar_t kChromeBinariesRegClientsKey[] =
+    L"Software\\Google\\Update\\Clients\\"
+    L"{4DC8B4CA-1BDA-483e-B5FA-D3C12E15B62D}";
+const wchar_t kChromeAppHostRegClientsKey[] =
+    L"Software\\Google\\Update\\Clients\\"
+    L"{FDA71E6F-AC4C-4a00-8B70-9958A68906BF}";
 
 const wchar_t kUninstallStringField[] = L"UninstallString";
 
+// Copied from util_constants.cc
+const wchar_t kSetupExe[] = L"setup.exe";
 const wchar_t kChromeExe[] = L"chrome.exe";
+namespace local_switches {

[erikwright (departed), 2012/09/12 15:53:50]

It's in an anonymous namespace already. I don't think the local_switches
namespace buys you anything.

[huangs, 2012/09/12 19:24:27]

Done.

+  const char kMultiInstall[] = "multi-install";
+  const char kChromeAppHost[] = "app-host";
+  const char kVerboseLogging[] = "verbose-logging";
+}
+
+// Copied from google_update_constants.cc
+const wchar_t kRegVersionField[] = L"pv";
 
 #ifndef OFFICIAL_BUILD
 FilePath GetDevelopmentChrome() {
   FilePath current_directory;
   if (PathService::Get(base::DIR_EXE, &current_directory)) {
     FilePath chrome_exe_path(current_directory.Append(kChromeExe));
     if (file_util::PathExists(chrome_exe_path))
       return chrome_exe_path;
   }
   return FilePath();
@@ skipping 11 matching lines @@
   chrome_path = GetDevelopmentChrome();
 #endif
   if (chrome_path.empty())
     chrome_path = GetChromePathForInstallationLevel(SYSTEM_LEVEL_INSTALLATION);
   if (chrome_path.empty())
     chrome_path = GetChromePathForInstallationLevel(USER_LEVEL_INSTALLATION);
 
   return chrome_path;
 }
 
+FilePath GetSetupExeForInstallationLevel(InstallationLevel level) {
+  using base::win::RegKey;
+  HKEY root_key = (level == USER_LEVEL_INSTALLATION ?
+                   HKEY_CURRENT_USER :
+                   HKEY_LOCAL_MACHINE);
+  RegKey reg_key;
+
+  LOG(INFO) << "Seeking reg: " << kChromeBinariesRegClientStateKey;
+
+  if (reg_key.Open(root_key, kChromeBinariesRegClientStateKey,
+      KEY_QUERY_VALUE) == ERROR_SUCCESS) {
+    // Grab the uninstall string from the appropriate ClientState key
+    // and use that as the base for a path to setup.exe.
+    string16 uninstall;
+    if (reg_key.ReadValue(kUninstallStringField, &uninstall) == ERROR_SUCCESS) {
+      // Trim the command line parameters.
+      FilePath setup_exe_path(CommandLine::FromString(uninstall).GetProgram());
+      LOG(INFO) << "Seeking file: " << setup_exe_path.value();
+      if (file_util::PathExists(setup_exe_path))
+        return setup_exe_path;
+    }
+  }
+
+  return FilePath();
+}
+
 FilePath GetChromePathForInstallationLevel(InstallationLevel level) {
   using base::win::RegKey;

[erikwright (departed), 2012/09/12 15:53:50]

this 'using' can go away.

[huangs, 2012/09/12 19:24:27]

Done.

-  HKEY root_key = (level == USER_LEVEL_INSTALLATION ?
-                   HKEY_CURRENT_USER :
-                   HKEY_LOCAL_MACHINE);
-  RegKey reg_key(root_key, kChromeRegClientStateKey, KEY_QUERY_VALUE);
-
   FilePath chrome_exe_path;

[erikwright (departed), 2012/09/12 15:53:50]

declaration of chrome_exe_path can go inside "if (!setup_exe_path.empty()) {"
(combined with assignment in line 112).

Then just move the "if (...) return chrome_exe_path" from line 122 inside the
scope ending at line 120.

[huangs, 2012/09/12 19:24:27]

Done.

-
-  if (reg_key.Valid()) {
-    // Now grab the uninstall string from the appropriate ClientState key
-    // and use that as the base for a path to chrome.exe.
-    string16 uninstall;
-    if (reg_key.ReadValue(kUninstallStringField, &uninstall) == ERROR_SUCCESS) {
-      // The uninstall path contains the path to setup.exe which is two levels
-      // down from chrome.exe. Move up two levels (plus one to drop the file
-      // name) and look for chrome.exe from there.
-      FilePath uninstall_path(uninstall);
+  FilePath setup_exe_path(GetSetupExeForInstallationLevel(level));
+  if (!setup_exe_path.empty()) {
+    // The uninstall path contains the path to setup.exe which is two levels
+    // down from chrome.exe. Move up two levels (plus one to drop the file
+    // name) and look for chrome.exe from there.
+    chrome_exe_path =
+        setup_exe_path.DirName().DirName().DirName().Append(kChromeExe);
+    if (!file_util::PathExists(chrome_exe_path)) {
+      // By way of mild future proofing, look up one to see if there's a
+      // chrome.exe in the version directory
       chrome_exe_path =
-          uninstall_path.DirName().DirName().DirName().Append(kChromeExe);
-      if (!file_util::PathExists(chrome_exe_path)) {
-        // By way of mild future proofing, look up one to see if there's a
-        // chrome.exe in the version directory
-        chrome_exe_path =
-            uninstall_path.DirName().DirName().Append(kChromeExe);
-      }
+          chrome_exe_path.DirName().DirName().Append(kChromeExe);
     }
   }
 
   if (file_util::PathExists(chrome_exe_path))
     return chrome_exe_path;
 
   return FilePath();
 }
 
+bool GetAppHostVersionString(string16* version_str) {

[erikwright (departed), 2012/09/12 15:53:50]

This should all be de-duped as:

GetAppVersionString(const char* app_guid, InstallationLevel level, string16*
version_str) {

}

[huangs, 2012/09/12 19:24:27]

Done, but updating Version* instead of string16*; also moved to
app_host_upgrade.cc.

+  using base::win::RegKey;
+  HKEY root_key = HKEY_CURRENT_USER;  // App Host is always user-level.
+  RegKey reg_key;
+  LOG(INFO) << "Trying to get " << kChromeAppHostRegClientsKey;
+  return (reg_key.Open(root_key, kChromeAppHostRegClientsKey, KEY_QUERY_VALUE)
+      == ERROR_SUCCESS) &&
+      (reg_key.ReadValue(kRegVersionField, version_str) == ERROR_SUCCESS);
+}
+
+bool GetChromeBinariesVersionStringForInstallationLevel(InstallationLevel level,
+                                                        string16* version_str) {
+  using base::win::RegKey;
+  HKEY root_key = (level == USER_LEVEL_INSTALLATION ?
+                   HKEY_CURRENT_USER :
+                   HKEY_LOCAL_MACHINE);
+  RegKey reg_key;
+  LOG(INFO) << "Trying to get " << kChromeBinariesRegClientsKey;
+  return (reg_key.Open(root_key, kChromeBinariesRegClientsKey, KEY_QUERY_VALUE)
+      == ERROR_SUCCESS) &&
+      (reg_key.ReadValue(kRegVersionField, version_str) == ERROR_SUCCESS);
+}
+
+bool GetAnyChromeBinariesVersionString(string16* version_str) {
+  return GetChromeBinariesVersionStringForInstallationLevel(
+      SYSTEM_LEVEL_INSTALLATION, version_str) ||
+      GetChromeBinariesVersionStringForInstallationLevel(
+          USER_LEVEL_INSTALLATION, version_str);
+}
+
+bool UpgradeAppHost() {
+  // Get the path to setup.exe, trying the system-level first.
+  FilePath setup_exe(
+      GetSetupExeForInstallationLevel(SYSTEM_LEVEL_INSTALLATION));
+  if (setup_exe.empty()) {
+    setup_exe = GetSetupExeForInstallationLevel(USER_LEVEL_INSTALLATION);
+  }
+  if (setup_exe.empty()) {
+    LOG(INFO) << "Failed to find setup.exe";
+    return false;
+  }
+  CommandLine cmd_line(setup_exe);
+  cmd_line.AppendSwitch(local_switches::kMultiInstall);
+  cmd_line.AppendSwitch(local_switches::kChromeAppHost);
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+      local_switches::kVerboseLogging)) {
+    cmd_line.AppendSwitch(local_switches::kVerboseLogging);
+  }
+  LOG(INFO) << "Command line: " << cmd_line.GetCommandLineString();
+  return base::LaunchProcess(cmd_line, base::LaunchOptions(), NULL);
+}
+
 }  // namespace chrome_launcher_support