Revert 285661 "Remove some dead app host code."

trunk/src/chrome/installer/launcher_support/chrome_launcher_support.cc

Index: trunk/src/chrome/installer/launcher_support/chrome_launcher_support.cc
===================================================================
--- trunk/src/chrome/installer/launcher_support/chrome_launcher_support.cc	(revision 285705)
+++ trunk/src/chrome/installer/launcher_support/chrome_launcher_support.cc	(working copy)
@@ -5,12 +5,20 @@
 #include "chrome/installer/launcher_support/chrome_launcher_support.h"
 
 #include <windows.h>
+#include <tchar.h>
 
+#include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
+#include "base/logging.h"
+#include "base/process/launch.h"
 #include "base/strings/string16.h"
 #include "base/win/registry.h"
 
+#ifndef OFFICIAL_BUILD
+#include "base/path_service.h"
+#endif
+
 namespace chrome_launcher_support {
 
 namespace {
@@ -18,6 +26,8 @@
 // TODO(huangs) Refactor the constants: http://crbug.com/148538
 const wchar_t kGoogleRegClientStateKey[] =
     L"Software\\Google\\Update\\ClientState";
+const wchar_t kGoogleRegClientsKey[] = L"Software\\Google\\Update\\Clients";
+const wchar_t kRegVersionField[] = L"pv";
 
 // Copied from chrome_appid.cc.
 const wchar_t kBinariesAppGuid[] = L"{4DC8B4CA-1BDA-483e-B5FA-D3C12E15B62D}";
@@ -25,8 +35,14 @@
 // Copied from google_chrome_distribution.cc.
 const wchar_t kBrowserAppGuid[] = L"{8A69D345-D564-463c-AFF1-A69D9E530F96}";
 
+// Copied frome google_chrome_sxs_distribution.cc.
+const wchar_t kSxSBrowserAppGuid[] = L"{4ea16ac7-fd5a-47c3-875b-dbf4a2008c20}";
+
 // Copied from util_constants.cc.
+const wchar_t kChromeAppHostExe[] = L"app_host.exe";
+const char kChromeAppLauncher[] = "app-launcher";
 const wchar_t kChromeExe[] = L"chrome.exe";
+const wchar_t kUninstallArgumentsField[] = L"UninstallArguments";
 const wchar_t kUninstallStringField[] = L"UninstallString";
 
 // Reads a string value from the specified product's "ClientState" registry key.
@@ -50,6 +66,33 @@
   return false;
 }
 
+// Determines whether the specified product has a key in "Clients". This
+// indicates whether the product is installed at the given level.
+bool IsProductInstalled(InstallationLevel level, const wchar_t* app_guid) {
+  HKEY root_key = (level == USER_LEVEL_INSTALLATION) ?
+      HKEY_CURRENT_USER : HKEY_LOCAL_MACHINE;
+  base::string16 subkey(kGoogleRegClientsKey);
+  subkey.append(1, L'\\').append(app_guid);
+  base::win::RegKey reg_key;
+  // Google Update always uses 32bit hive.
+  return reg_key.Open(root_key, subkey.c_str(),
+                      KEY_QUERY_VALUE | KEY_WOW64_32KEY) == ERROR_SUCCESS &&
+      reg_key.HasValue(kRegVersionField);
+}
+
+bool IsAppLauncherEnabledAtLevel(InstallationLevel level) {
+  base::string16 uninstall_arguments;
+  if (GetClientStateValue(level,
+                          kAppLauncherGuid,
+                          kUninstallArgumentsField,
+                          &uninstall_arguments)) {
+    return CommandLine::FromString(L"dummy.exe " + uninstall_arguments)
+        .HasSwitch(kChromeAppLauncher) &&
+        !GetAppHostPathForInstallationLevel(level).empty();
+  }
+  return false;
+}
+
 // Reads the path to setup.exe from the value "UninstallString" within the
 // specified product's "ClientState" registry key. Returns an empty FilePath if
 // an error occurs or the product is not installed at the specified level.
@@ -64,22 +107,9 @@
   return base::FilePath();
 }
 
-// Returns the path to an existing setup.exe at the specified level, if it can
-// be found via Omaha client state.
-base::FilePath GetSetupExeForInstallationLevel(InstallationLevel level) {
-  // Look in the registry for Chrome Binaries first.
-  base::FilePath setup_exe_path(
-      GetSetupExeFromRegistry(level, kBinariesAppGuid));
-  // If the above fails, look in the registry for Chrome next.
-  if (setup_exe_path.empty())
-    setup_exe_path = GetSetupExeFromRegistry(level, kBrowserAppGuid);
-  // If we fail again, then setup_exe_path would be empty.
-  return setup_exe_path;
-}
-
-// Returns the path to an installed |exe_file| (e.g. chrome.exe) at the
-// specified level, given |setup_exe_path| from Omaha client state.  Returns
-// empty base::FilePath if none found, or if |setup_exe_path| is empty.
+// Returns the path to an installed |exe_file| (e.g. chrome.exe, app_host.exe)
+// at the specified level, given |setup_exe_path| from Omaha client state.
+// Returns empty base::FilePath if none found, or if |setup_exe_path| is empty.
 base::FilePath FindExeRelativeToSetupExe(const base::FilePath setup_exe_path,
                                          const wchar_t* exe_file) {
   if (!setup_exe_path.empty()) {
@@ -101,11 +131,52 @@
 
 }  // namespace
 
+const wchar_t kAppLauncherGuid[] = L"{FDA71E6F-AC4C-4a00-8B70-9958A68906BF}";
+
+void UninstallLegacyAppLauncher(InstallationLevel level) {
+  base::FilePath setup_exe(GetSetupExeFromRegistry(level, kAppLauncherGuid));
+  if (setup_exe.empty())
+    return;
+  base::string16 uninstall_arguments;
+  if (GetClientStateValue(level,
+                          kAppLauncherGuid,
+                          kUninstallArgumentsField,
+                          &uninstall_arguments)) {
+    CommandLine uninstall_cmd = CommandLine::FromString(
+        L"\"" + setup_exe.value() + L"\" " + uninstall_arguments);
+
+    VLOG(1) << "Uninstalling legacy app launcher with command line: "
+            << uninstall_cmd.GetCommandLineString();
+    base::LaunchProcess(uninstall_cmd, base::LaunchOptions(), NULL);
+  }
+}
+
+base::FilePath GetSetupExeForInstallationLevel(InstallationLevel level) {
+  // Look in the registry for Chrome Binaries first.
+  base::FilePath setup_exe_path(
+      GetSetupExeFromRegistry(level, kBinariesAppGuid));
+  // If the above fails, look in the registry for Chrome next.
+  if (setup_exe_path.empty())
+    setup_exe_path = GetSetupExeFromRegistry(level, kBrowserAppGuid);
+  // If we fail again, then setup_exe_path would be empty.
+  return setup_exe_path;
+}
+
 base::FilePath GetChromePathForInstallationLevel(InstallationLevel level) {
   return FindExeRelativeToSetupExe(
       GetSetupExeForInstallationLevel(level), kChromeExe);
 }
 
+base::FilePath GetAppHostPathForInstallationLevel(InstallationLevel level) {
+  return FindExeRelativeToSetupExe(
+      GetSetupExeFromRegistry(level, kAppLauncherGuid), kChromeAppHostExe);
+}
+
+base::FilePath GetChromeSxSPathForInstallationLevel(InstallationLevel level) {
+  return FindExeRelativeToSetupExe(
+      GetSetupExeFromRegistry(level, kSxSBrowserAppGuid), kChromeExe);
+}
+
 base::FilePath GetAnyChromePath() {
   base::FilePath chrome_path;
   if (chrome_path.empty())
@@ -115,4 +186,47 @@
   return chrome_path;
 }
 
+base::FilePath GetAnyAppHostPath() {
+  base::FilePath app_host_path;
+  if (app_host_path.empty()) {
+    app_host_path = GetAppHostPathForInstallationLevel(
+        SYSTEM_LEVEL_INSTALLATION);
+  }
+  if (app_host_path.empty())
+    app_host_path = GetAppHostPathForInstallationLevel(USER_LEVEL_INSTALLATION);
+  return app_host_path;
+}
+
+base::FilePath GetAnyChromeSxSPath() {
+  base::FilePath path =
+      GetChromeSxSPathForInstallationLevel(USER_LEVEL_INSTALLATION);
+  if (path.empty())
+    path = GetChromeSxSPathForInstallationLevel(SYSTEM_LEVEL_INSTALLATION);
+  return path;
+}
+
+bool IsAppHostPresent() {
+  base::FilePath app_host_exe = GetAnyAppHostPath();
+  return !app_host_exe.empty();
+}
+
+InstallationState GetAppLauncherInstallationState() {
+  if (IsAppLauncherEnabledAtLevel(SYSTEM_LEVEL_INSTALLATION))
+    return INSTALLED_AT_SYSTEM_LEVEL;
+
+  if (IsAppLauncherEnabledAtLevel(USER_LEVEL_INSTALLATION))
+    return INSTALLED_AT_USER_LEVEL;
+
+  return NOT_INSTALLED;
+}
+
+bool IsAppLauncherPresent() {
+  return GetAppLauncherInstallationState() != NOT_INSTALLED;
+}
+
+bool IsChromeBrowserPresent() {
+  return IsProductInstalled(USER_LEVEL_INSTALLATION, kBrowserAppGuid) ||
+      IsProductInstalled(SYSTEM_LEVEL_INSTALLATION, kBrowserAppGuid);
+}
+
 }  // namespace chrome_launcher_support