Move app_host code from extensions into src/apps.

BUG=None


Review URL: https://chromiumcodereview.appspot.com/12310059

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@184295 0039d316-1c4b-4281-b951-d872f2087c98

10 files changed, 611 insertions, 0 deletions

diff --git a/apps/app_host/DEPS b/apps/app_host/DEPS
new file mode 100644
index 0000000..7251c42
--- /dev/null
+++ b/apps/app_host/DEPS
@@ -0,0 +1,3 @@
+include_rules = [
+  "+google_update",
+]
diff --git a/apps/app_host/OWNERS b/apps/app_host/OWNERS
new file mode 100644
index 0000000..82e44d8
--- /dev/null
+++ b/apps/app_host/OWNERS
@@ -0,0 +1 @@
+erikwright@chromium.org
diff --git a/apps/app_host/app_host.rc b/apps/app_host/app_host.rc
new file mode 100644
index 0000000..f4fedec
--- /dev/null
+++ b/apps/app_host/app_host.rc
@@ -0,0 +1,46 @@
+// Microsoft Visual C++ generated resource script.
+//
+#include "app_host_resource.h"
+
+#define APSTUDIO_READONLY_SYMBOLS
+/////////////////////////////////////////////////////////////////////////////
+//
+// Generated from the TEXTINCLUDE 2 resource.
+//
+#define APSTUDIO_HIDDEN_SYMBOLS
+#include "windows.h"
+#undef APSTUDIO_HIDDEN_SYMBOLS
+
+/////////////////////////////////////////////////////////////////////////////
+#undef APSTUDIO_READONLY_SYMBOLS
+
+/////////////////////////////////////////////////////////////////////////////
+// English (U.S.) resources
+
+#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
+#ifdef _WIN32
+LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
+#pragma code_page(1252)
+#endif //_WIN32
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// Icon
+//
+
+// Icon with lowest ID value placed first to ensure application icon
+// remains consistent on all systems.
+IDI_APP_HOST_MAIN  ICON  "..\\..\\chrome\\app\\theme\\app_list.ico"
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// GOOGLEUPDATEAPPLICATIONCOMMANDS is a "well-known" marker resource defined
+// by Omaha. Executables must both be signed by Google and contain the marker
+// in order to expose application commands.
+//
+#define IDR_GOOGLE_UPDATE_APP_COMMANDS_MARKUP 1
+
+IDR_GOOGLE_UPDATE_APP_COMMANDS_MARKUP GOOGLEUPDATEAPPLICATIONCOMMANDS { 1L }
+
+#endif    // English (U.S.) resources
+/////////////////////////////////////////////////////////////////////////////
diff --git a/apps/app_host/app_host_main.cc b/apps/app_host/app_host_main.cc
new file mode 100644
index 0000000..64de547
--- /dev/null
+++ b/apps/app_host/app_host_main.cc
@@ -0,0 +1,53 @@
+// 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 <windows.h>
+
+#include "apps/app_host/binaries_installer.h"
+#include "apps/app_host/update.h"
+#include "base/at_exit.h"
+#include "base/command_line.h"
+#include "base/file_path.h"
+#include "base/logging.h"
+#include "base/process_util.h"
+#include "chrome/installer/launcher_support/chrome_launcher_support.h"
+
+int APIENTRY wWinMain(HINSTANCE, HINSTANCE, wchar_t*, int) {
+  base::AtExitManager exit_manager;
+
+  // Initialize the commandline singleton from the environment.
+  CommandLine::Init(0, NULL);
+
+  base::FilePath chrome_exe(chrome_launcher_support::GetAnyChromePath());
+  if (chrome_exe.empty()) {
+    LOG(INFO) << "No Chrome executable could be found. Let's install it.";
+    HRESULT hr = app_host::InstallBinaries();
+    if (FAILED(hr)) {
+      LOG(ERROR) << "Failed to install the Chrome Binaries. Error: " << hr;
+      return 1;
+    } else {
+      chrome_exe = chrome_launcher_support::GetAnyChromePath();
+      if (chrome_exe.empty()) {
+        LOG(ERROR) << "Failed to find the Chrome Binaries despite a "
+                   << "'successful' installation.";
+        return 1;
+      }
+    }
+  }
+
+  CommandLine chrome_exe_command_line(chrome_exe);
+  chrome_exe_command_line.AppendArguments(
+      *CommandLine::ForCurrentProcess(), false);
+  // Launch Chrome before checking for update, for faster user experience.
+  bool launch_result = base::LaunchProcess(chrome_exe_command_line,
+                                           base::LaunchOptions(), NULL);
+  if (launch_result)
+    LOG(INFO) << "Delegated to Chrome executable at " << chrome_exe.value();
+  else
+    LOG(INFO) << "Failed to launch Chrome executable at " << chrome_exe.value();
+
+  app_host::EnsureAppHostUpToDate();
+
+  return !launch_result;
+}
diff --git a/apps/app_host/app_host_resource.h b/apps/app_host/app_host_resource.h
new file mode 100644
index 0000000..29d289c
--- /dev/null
+++ b/apps/app_host/app_host_resource.h
@@ -0,0 +1,5 @@
+// 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.
+
+#define IDI_APP_HOST_MAIN               101
diff --git a/apps/app_host/binaries_installer.cc b/apps/app_host/binaries_installer.cc
new file mode 100644
index 0000000..ce72888
--- /dev/null
+++ b/apps/app_host/binaries_installer.cc
@@ -0,0 +1,327 @@
+// 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 "apps/app_host/binaries_installer.h"
+
+#include "base/logging.h"
+#include "base/threading/platform_thread.h"
+#include "base/win/scoped_bstr.h"
+#include "base/win/scoped_com_initializer.h"
+#include "base/win/scoped_comptr.h"
+#include "google_update/google_update_idl.h"
+
+
+namespace app_host {
+
+// Helpers --------------------------------------------------------------------
+
+namespace {
+
+const wchar_t kAppHostAppId[] = L"{FDA71E6F-AC4C-4a00-8B70-9958A68906BF}";
+const wchar_t kBinariesAppId[] = L"{4DC8B4CA-1BDA-483e-B5FA-D3C12E15B62D}";
+const int kInstallationPollingIntervalMs = 50;
+
+HRESULT CreateInstalledApp(IAppBundle* app_bundle,
+                           const wchar_t* app_guid,
+                           IApp** app) {
+  base::win::ScopedComPtr<IDispatch> idispatch;
+  HRESULT hr = app_bundle->createInstalledApp(base::win::ScopedBstr(app_guid),
+                                              idispatch.Receive());
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Failed to configure App Bundle: " << hr;
+    return hr;
+  }
+
+  base::win::ScopedComPtr<IApp> temp_app;
+  hr = temp_app.QueryFrom(idispatch);
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Unexpected error querying IApp from "
+               << "IAppBundle->createInstalledApp return value: " << hr;
+  } else {
+    *app = temp_app.Detach();
+  }
+  return hr;
+}
+
+HRESULT GetAppHostApValue(IGoogleUpdate3* update3,
+                          IAppBundle* app_bundle,
+                          BSTR* ap_value) {
+  base::win::ScopedComPtr<IApp> app;
+  HRESULT hr = CreateInstalledApp(app_bundle, kAppHostAppId, app.Receive());
+  if (FAILED(hr))
+    return hr;
+
+  hr = app->get_ap(ap_value);
+  if (FAILED(hr))
+    LOG(ERROR) << "Failed to get the App Launcher AP value.";
+  return hr;
+}
+
+HRESULT GetCurrentState(IApp* app,
+                        ICurrentState** current_state,
+                        CurrentState* state_value) {
+  base::win::ScopedComPtr<IDispatch> idispatch;
+  HRESULT hr = app->get_currentState(idispatch.Receive());
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Failed to get App Bundle state: " << hr;
+    return hr;
+  }
+
+  base::win::ScopedComPtr<ICurrentState> temp_current_state;
+  hr = temp_current_state.QueryFrom(idispatch);
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Unexpected error querying ICurrentState from "
+               << "IApp::get_currentState return value: " << hr;
+    return hr;
+  }
+
+  LONG long_state_value;
+  hr = temp_current_state->get_stateValue(&long_state_value);
+  if (SUCCEEDED(hr)) {
+    *state_value = static_cast<CurrentState>(long_state_value);
+    *current_state = temp_current_state.Detach();
+  } else {
+    LOG(ERROR) << "Failed to get App Bundle state value: " << hr;
+  }
+  return hr;
+}
+
+bool CheckIsBusy(IAppBundle* app_bundle, HRESULT* hr) {
+  VARIANT_BOOL variant_is_busy = VARIANT_TRUE;
+  *hr = app_bundle->isBusy(&variant_is_busy);
+  if (FAILED(*hr))
+    LOG(ERROR) << "Failed to check app_bundle->isBusy: " << *hr;
+  return (variant_is_busy == VARIANT_TRUE);
+}
+
+void OnUpdateAvailable(IAppBundle* app_bundle, HRESULT* hr) {
+  // If the app bundle is busy we will just wait some more.
+  if (CheckIsBusy(app_bundle, hr) || FAILED(*hr))
+    return;
+  *hr = app_bundle->download();
+  if (FAILED(*hr))
+    LOG(ERROR) << "Failed to initiate bundle download: " << *hr;
+}
+
+void OnReadyToInstall(IAppBundle* app_bundle, HRESULT* hr) {
+  // If the app bundle is busy we will just wait some more.
+  if (CheckIsBusy(app_bundle, hr) || FAILED(*hr))
+    return;
+  *hr = app_bundle->install();
+  if (FAILED(*hr))
+    LOG(ERROR) << "Failed to initiate bundle install: " << *hr;
+}
+
+HRESULT OnError(ICurrentState* current_state) {
+  LONG error_code;
+  HRESULT hr = current_state->get_errorCode(&error_code);
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Failed to retrieve bundle error code: " << hr;
+    return hr;
+  }
+
+  base::win::ScopedBstr completion_message;
+  HRESULT completion_message_hr =
+    current_state->get_completionMessage(completion_message.Receive());
+  if (FAILED(completion_message_hr)) {
+    LOG(ERROR) << "Bundle installation failed with error " << error_code
+               << ". Error message retrieval failed with error: "
+               << completion_message_hr;
+  } else {
+    LOG(ERROR) << "Bundle installation failed with error " << error_code << ": "
+               << completion_message;
+  }
+  return error_code;
+}
+
+HRESULT CreateGoogleUpdate3(IGoogleUpdate3** update3) {
+  base::win::ScopedComPtr<IGoogleUpdate3> temp_update3;
+  HRESULT hr = temp_update3.CreateInstance(CLSID_GoogleUpdate3UserClass);
+  if (SUCCEEDED(hr)) {
+    *update3 = temp_update3.Detach();
+  } else {
+    // TODO(erikwright): Try in-proc to support running elevated? According
+    // to update3_utils.cc (CreateGoogleUpdate3UserClass):
+    // The primary reason for the LocalServer activation failing on Vista/Win7
+    // is that COM does not look at HKCU registration when the code is running
+    // elevated. We fall back to an in-proc mode. The in-proc mode is limited to
+    // one install at a time, so we use it only as a backup mechanism.
+    LOG(ERROR) << "Failed to instantiate GoogleUpdate3: " << hr;
+  }
+  return hr;
+}
+
+HRESULT CreateAppBundle(IGoogleUpdate3* update3, IAppBundle** app_bundle) {
+  base::win::ScopedComPtr<IDispatch> idispatch;
+  HRESULT hr = update3->createAppBundle(idispatch.Receive());
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Failed to createAppBundle: " << hr;
+    return hr;
+  }
+
+  base::win::ScopedComPtr<IAppBundle> temp_app_bundle;
+  hr = temp_app_bundle.QueryFrom(idispatch);
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Unexpected error querying IAppBundle from "
+               << "IGoogleUpdate3->createAppBundle return value: " << hr;
+    return hr;
+  }
+
+  hr = temp_app_bundle->initialize();
+  if (FAILED(hr))
+    LOG(ERROR) << "Failed to initialize App Bundle: " << hr;
+  else
+    *app_bundle = temp_app_bundle.Detach();
+  return hr;
+}
+
+HRESULT SelectBinariesApValue(IGoogleUpdate3* update3,
+                              IAppBundle* app_bundle,
+                              BSTR* ap_value) {
+  HRESULT hr = GetAppHostApValue(update3, app_bundle, ap_value);
+  if (SUCCEEDED(hr))
+    return hr;
+
+  // TODO(erikwright): distinguish between AppHost not installed and an
+  // error in GetAppHostApValue.
+  // TODO(erikwright): Use stable by default when App Host support is in
+  // stable.
+  base::win::ScopedBstr temp_ap_value;
+  if (temp_ap_value.Allocate(L"2.0-dev-multi-apphost") == NULL) {
+    LOG(ERROR) << "Unexpected error in ScopedBstr::Allocate.";
+    return E_FAIL;
+  }
+  *ap_value = temp_ap_value.Release();
+  return S_OK;
+}
+
+HRESULT CreateBinariesIApp(IAppBundle* app_bundle, BSTR ap, IApp** app) {
+  base::win::ScopedComPtr<IDispatch> idispatch;
+  HRESULT hr = app_bundle->createApp(base::win::ScopedBstr(kBinariesAppId),
+                                     idispatch.Receive());
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Failed to configure App Bundle: " << hr;
+    return hr;
+  }
+
+  base::win::ScopedComPtr<IApp> temp_app;
+  hr = temp_app.QueryFrom(idispatch);
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Unexpected error querying IApp from "
+               << "IAppBundle->createApp return value: " << hr;
+    return hr;
+  }
+
+  hr = temp_app->put_isEulaAccepted(VARIANT_TRUE);
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Failed to set 'EULA Accepted': " << hr;
+    return hr;
+  }
+
+  hr = temp_app->put_ap(ap);
+  if (FAILED(hr))
+    LOG(ERROR) << "Failed to set AP value: " << hr;
+  else
+    *app = temp_app.Detach();
+  return hr;
+}
+
+bool CheckIfDone(IAppBundle* app_bundle, IApp* app, HRESULT* hr) {
+  base::win::ScopedComPtr<ICurrentState> current_state;
+  CurrentState state_value;
+  *hr = GetCurrentState(app, current_state.Receive(), &state_value);
+  if (FAILED(*hr))
+    return true;
+
+  switch (state_value) {
+    case STATE_WAITING_TO_CHECK_FOR_UPDATE:
+    case STATE_CHECKING_FOR_UPDATE:
+    case STATE_WAITING_TO_DOWNLOAD:
+    case STATE_RETRYING_DOWNLOAD:
+    case STATE_DOWNLOADING:
+    case STATE_WAITING_TO_INSTALL:
+    case STATE_INSTALLING:
+    case STATE_DOWNLOAD_COMPLETE:
+    case STATE_EXTRACTING:
+    case STATE_APPLYING_DIFFERENTIAL_PATCH:
+      // These states will all transition on their own.
+      return false;
+
+    case STATE_UPDATE_AVAILABLE:
+      OnUpdateAvailable(app_bundle, hr);
+      return FAILED(*hr);
+
+    case STATE_READY_TO_INSTALL:
+      OnReadyToInstall(app_bundle, hr);
+      return FAILED(*hr);
+
+    case STATE_NO_UPDATE:
+      LOG(INFO) << "Google Update reports that the binaries are already "
+                << "installed and up-to-date.";
+      return true;
+
+    case STATE_INSTALL_COMPLETE:
+      return true;
+
+    case STATE_ERROR:
+      *hr = OnError(current_state);
+      return FAILED(*hr);
+
+    case STATE_INIT:
+    case STATE_PAUSED:
+    default:
+      LOG(ERROR) << "Unexpected bundle state: " << state_value << ".";
+      *hr = E_FAIL;
+      return true;
+  }
+}
+
+}  // namespace
+
+
+// Globals --------------------------------------------------------------------
+
+HRESULT InstallBinaries() {
+  base::win::ScopedCOMInitializer initialize_com;
+  if (!initialize_com.succeeded()) {
+    LOG(ERROR) << "COM initialization failed";
+    return E_FAIL;
+  }
+
+  base::win::ScopedComPtr<IGoogleUpdate3> update3;
+  HRESULT hr = CreateGoogleUpdate3(update3.Receive());
+  if (FAILED(hr))
+    return hr;
+
+  base::win::ScopedComPtr<IAppBundle> app_bundle;
+  hr = CreateAppBundle(update3, app_bundle.Receive());
+  if (FAILED(hr))
+    return hr;
+
+  base::win::ScopedBstr ap_value;
+  hr = SelectBinariesApValue(update3, app_bundle, ap_value.Receive());
+  if (FAILED(hr))
+    return hr;
+
+  base::win::ScopedComPtr<IApp> app;
+  hr = CreateBinariesIApp(app_bundle, ap_value, app.Receive());
+  if (FAILED(hr))
+    return hr;
+
+  hr = app_bundle->checkForUpdate();
+  if (FAILED(hr)) {
+    LOG(ERROR) << "Failed to initiate update check: " << hr;
+    return hr;
+  }
+
+  // We rely upon Omaha to eventually time out and transition to a failure
+  // state.
+  while (!CheckIfDone(app_bundle, app, &hr)) {
+    base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(
+        kInstallationPollingIntervalMs));
+  }
+  return hr;
+}
+
+}  // namespace app_host
diff --git a/apps/app_host/binaries_installer.h b/apps/app_host/binaries_installer.h
new file mode 100644
index 0000000..8c70146
--- /dev/null
+++ b/apps/app_host/binaries_installer.h
@@ -0,0 +1,19 @@
+// 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.
+
+#ifndef APPS_APP_HOST_BINARIES_INSTALLER_H_
+#define APPS_APP_HOST_BINARIES_INSTALLER_H_
+
+#include <windows.h>
+
+namespace app_host {
+
+// Attempts to install the Chrome Binaries. Blocks until the installation
+// process is complete. The AP value, if any, from the currently installed App
+// Host will be used.
+HRESULT InstallBinaries();
+
+}  // namespace app_host
+
+#endif  // APPS_APP_HOST_BINARIES_INSTALLER_H_
diff --git a/apps/app_host/update.cc b/apps/app_host/update.cc
new file mode 100644
index 0000000..e8b14be8
--- /dev/null
+++ b/apps/app_host/update.cc
@@ -0,0 +1,102 @@
+// 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 "apps/app_host/update.h"
+
+#include <windows.h>
+#include "base/command_line.h"
+#include "base/file_version_info.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/process_util.h"
+#include "base/string16.h"
+#include "base/string_util.h"
+#include "base/version.h"
+#include "base/win/registry.h"
+#include "chrome/installer/launcher_support/chrome_launcher_support.h"
+
+namespace app_host {
+
+namespace {
+
+// TODO(huangs) Refactor the constants: http://crbug.com/148538
+const wchar_t kGoogleRegClientsKey[] = L"Software\\Google\\Update\\Clients\\";
+
+// Copied from util_constants.cc.
+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";
+
+// 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}";
+
+// Fetches the version of the App Host, directly from the image's version
+// resource.
+Version GetAppHostVersion() {
+  scoped_ptr<FileVersionInfo> version_info(
+      FileVersionInfo::CreateFileVersionInfoForCurrentModule());
+  Version app_host_version(WideToASCII(version_info->product_version()));
+  DCHECK(app_host_version.IsValid());
+  return app_host_version;
+}
+
+// Fetches the app version ("pv" entry) of a Google product from the
+// system-level registry, given the app GUID ("{###...###}").
+Version GetAppVersionFromRegistry(const wchar_t* app_guid) {
+  HKEY root_key = HKEY_LOCAL_MACHINE;
+  string16 client_key(kGoogleRegClientsKey);
+  client_key.append(app_guid);
+  base::win::RegKey reg_key;
+  string16 version_str;
+  if ((reg_key.Open(root_key, client_key.c_str(),
+                    KEY_QUERY_VALUE) == ERROR_SUCCESS) &&
+      (reg_key.ReadValue(kRegVersionField, &version_str) == ERROR_SUCCESS)) {
+    return Version(WideToASCII(version_str));
+  }
+  return Version();
+}
+
+// Calls setup.exe to update App Host, using the system-level setup.exe.
+bool LaunchAppHostUpdate() {
+  // Get the path to the setup.exe.
+  base::FilePath setup_exe(
+      chrome_launcher_support::GetSetupExeForInstallationLevel(
+          chrome_launcher_support::SYSTEM_LEVEL_INSTALLATION));
+  if (setup_exe.empty()) {
+    LOG(ERROR) << "Failed to find setup.exe";
+    return false;
+  }
+  CommandLine cmd_line(setup_exe);
+  cmd_line.AppendSwitch(kMultiInstall);
+  cmd_line.AppendSwitch(kChromeAppHost);
+  cmd_line.AppendSwitch(kVerboseLogging);
+  LOG(INFO) << "Launching: " << cmd_line.GetCommandLineString();
+  return base::LaunchProcess(cmd_line, base::LaunchOptions(), NULL);
+}
+
+}  // namespace
+
+void EnsureAppHostUpToDate() {
+  // Check version from Chrome Binaries first, then Chrome (all system-level).
+  Version new_version(GetAppVersionFromRegistry(kBinariesAppGuid));
+  if (!new_version.IsValid())
+    new_version = GetAppVersionFromRegistry(kBrowserAppGuid);
+  if (!new_version.IsValid())
+    return;  // Not an error: System-level Chrome might not be installed.
+  Version app_host_version(GetAppHostVersion());
+  if (app_host_version.CompareTo(new_version) < 0) {
+    LOG(INFO) << "Updating App Launcher from " << app_host_version.GetString()
+              << " to " << new_version.GetString();
+    if (!LaunchAppHostUpdate())
+      LOG(ERROR) << "Failed to launch App Launcher update.";
+  }
+}
+
+}  // namespace app_host
diff --git a/apps/app_host/update.h b/apps/app_host/update.h
new file mode 100644
index 0000000..b72c985
--- /dev/null
+++ b/apps/app_host/update.h
@@ -0,0 +1,16 @@
+// 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.
+
+#ifndef APPS_APP_HOST_UPDATE_H_
+#define APPS_APP_HOST_UPDATE_H_
+
+namespace app_host {
+
+// If system-level Chrome Binary is installed, and if its version is
+// newer than App Host's, then udpate App Host by calling setup.exe.
+void EnsureAppHostUpToDate();
+
+}  // namespace app_host
+
+#endif  // APPS_APP_HOST_UPDATE_H_
diff --git a/apps/apps.gypi b/apps/apps.gypi
index 257195d..76bca7e 100644
--- a/apps/apps.gypi
+++ b/apps/apps.gypi
@@ -44,4 +44,43 @@
       'msvs_disabled_warnings': [ 4267, ],
     },
   ],
+  'conditions': [
+    ['OS=="win"', {
+      'targets': [
+        {
+          'target_name': 'app_host',
+          'type': 'executable',
+          'include_dirs': [
+              '..',
+            ],
+          'direct_dependent_settings': {
+            'include_dirs': [
+              '..',
+            ],
+          },
+          'dependencies': [
+            '<(DEPTH)/base/base.gyp:base',
+            '<(DEPTH)/chrome/chrome.gyp:chrome_version_resources',
+            '<(DEPTH)/chrome/chrome.gyp:launcher_support',
+            '<(DEPTH)/google_update/google_update.gyp:google_update',
+          ],
+          'sources': [
+            'app_host/app_host.rc',
+            'app_host/app_host_main.cc',
+            'app_host/app_host_resource.h',
+            'app_host/binaries_installer.cc',
+            'app_host/binaries_installer.h',
+            'app_host/update.cc',
+            'app_host/update.h',
+            '<(SHARED_INTERMEDIATE_DIR)/chrome_version/app_host_exe_version.rc',
+          ],
+          'msvs_settings': {
+            'VCLinkerTool': {
+              'SubSystem': '2',  # Set /SUBSYSTEM:WINDOWS
+            },
+          },
+        },
+      ],
+    },],  # 'OS=="win"'
+  ],  # 'conditions'
 }