Move app_installer into chromium.

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 "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/strings/string16.h"
 #include "base/win/registry.h"
 
 namespace chrome_launcher_support {
 
 namespace {
 
 // TODO(huangs) Refactor the constants: http://crbug.com/148538
 const wchar_t kGoogleRegClientStateKey[] =
     L"Software\\Google\\Update\\ClientState";
 
 // Copied from chrome_appid.cc.
 const wchar_t kBinariesAppGuid[] = L"{4DC8B4CA-1BDA-483e-B5FA-D3C12E15B62D}";
 
 // 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 kChromeExe[] = L"chrome.exe";
 const wchar_t kUninstallStringField[] = L"UninstallString";
 
 // Reads a string value from the specified product's "ClientState" registry key.
 // Returns true iff the value is present and successfully read.
 bool GetClientStateValue(InstallationLevel level,
                          const wchar_t* app_guid,
                          const wchar_t* value_name,
                          base::string16* value) {
@@ skipping 54 matching lines @@
       return exe_path;
     // By way of mild future proofing, look up one to see if there's a
     // |exe_file| in the version directory
     exe_path = setup_exe_path.DirName().DirName().Append(exe_file);
     if (base::PathExists(exe_path))
       return exe_path;
   }
   return base::FilePath();
 }
 
+// Returns the path to an installed SxS chrome.exe at the specified level, if
+// it can be found via Omaha client state.
+base::FilePath GetChromeSxSPathForInstallationLevel(InstallationLevel level) {
+  return FindExeRelativeToSetupExe(
+      GetSetupExeFromRegistry(level, kSxSBrowserAppGuid), kChromeExe);
+}
+
 }  // namespace
 
 base::FilePath GetChromePathForInstallationLevel(InstallationLevel level) {
   return FindExeRelativeToSetupExe(
       GetSetupExeForInstallationLevel(level), kChromeExe);
 }
 
 base::FilePath GetAnyChromePath() {
   base::FilePath chrome_path;
   if (chrome_path.empty())
     chrome_path = GetChromePathForInstallationLevel(SYSTEM_LEVEL_INSTALLATION);
   if (chrome_path.empty())
     chrome_path = GetChromePathForInstallationLevel(USER_LEVEL_INSTALLATION);
   return chrome_path;
 }
 
+base::FilePath GetAnyChromeSxSPath() {
+  base::FilePath path =
+      GetChromeSxSPathForInstallationLevel(USER_LEVEL_INSTALLATION);

[Matt Giuca, 2014/10/30 02:33:07]

Is there a reason this prioritizes user-level installation, whereas
GetAnyChromePath prioritizes system-level?

[Matt Giuca, 2014/10/30 02:55:44]

Just asked the same question on:
https://codereview.chromium.org/685103004
feel free to ignore this and answer it there.

+  if (path.empty())
+    path = GetChromeSxSPathForInstallationLevel(SYSTEM_LEVEL_INSTALLATION);
+  return path;
+}
+
 }  // namespace chrome_launcher_support