// 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/common/chrome_paths.h"

#include "base/files/file_util.h"
#include "base/logging.h"
#include "base/native_library.h"
#include "base/no_destructor.h"
#include "base/path_service.h"
#include "base/strings/string_util.h"
#include "base/system/sys_info.h"
#include "base/threading/thread_restrictions.h"
#include "base/version.h"
#include "build/build_config.h"
#include "chrome/common/buildflags.h"
#include "chrome/common/chrome_constants.h"
#include "chrome/common/chrome_paths_internal.h"
#include "media/media_buildflags.h"
#include "third_party/widevine/cdm/buildflags.h"

#if defined(OS_ANDROID)
#include "base/android/path_utils.h"
#include "base/base_paths_android.h"
// ui/base must only be used on Android. See BUILD.gn for dependency info.
#include "ui/base/ui_base_paths.h"  // nogncheck
#endif

#if defined(OS_MACOSX)
#include "base/mac/bundle_locations.h"
#include "base/mac/foundation_util.h"
#endif

#if defined(OS_WIN)
#include "base/win/registry.h"
#endif

#if BUILDFLAG(ENABLE_WIDEVINE) && BUILDFLAG(ENABLE_LIBRARY_CDMS)
#include "media/cdm/cdm_paths.h"                           // nogncheck
#include "third_party/widevine/cdm/widevine_cdm_common.h"  // nogncheck
#endif

namespace {

// The Pepper Flash plugins are in a directory with this name.
const base::FilePath::CharType kPepperFlashBaseDirectory[] =
    FILE_PATH_LITERAL("PepperFlash");

#if defined(OS_MACOSX)
const base::FilePath::CharType kPepperFlashSystemBaseDirectory[] =
    FILE_PATH_LITERAL("Internet Plug-Ins/PepperFlashPlayer");
#endif

#if defined(OS_LINUX)
// The path to the external extension <id>.json files.
// /usr/share seems like a good choice, see: http://www.pathname.com/fhs/
const base::FilePath::CharType kFilepathSinglePrefExtensions[] =
#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
    FILE_PATH_LITERAL("/usr/share/google-chrome/extensions");
#else
    FILE_PATH_LITERAL("/usr/share/chromium/extensions");
#endif  // BUILDFLAG(GOOGLE_CHROME_BRANDING)

// The path to the hint file that tells the pepper plugin loader
// where it can find the latest component updated flash.
const base::FilePath::CharType kComponentUpdatedFlashHint[] =
    FILE_PATH_LITERAL("latest-component-updated-flash");
#endif  // defined(OS_LINUX)

#if defined(OS_CHROMEOS)
const base::FilePath::CharType kChromeOSComponentFlash[] = FILE_PATH_LITERAL(
    "/run/imageloader/PepperFlashPlayer/libpepflashplayer.so");
const base::FilePath::CharType kChromeOSTPMFirmwareUpdateLocation[] =
    FILE_PATH_LITERAL("/run/tpm_firmware_update_location");
const base::FilePath::CharType kChromeOSTPMFirmwareUpdateSRKVulnerableROCA[] =
    FILE_PATH_LITERAL("/run/tpm_firmware_update_srk_vulnerable_roca");
#endif  // defined(OS_CHROMEOS)

base::FilePath& GetInvalidSpecifiedUserDataDirInternal() {
  static base::NoDestructor<base::FilePath> s;
  return *s;
}

// Gets the path for internal plugins.
bool GetInternalPluginsDirectory(base::FilePath* result) {
#if defined(OS_MACOSX)
  // If called from Chrome, get internal plugins from a subdirectory of the
  // framework.
  if (base::mac::AmIBundled()) {
    *result = chrome::GetFrameworkBundlePath();
    DCHECK(!result->empty());
    *result = result->Append("Internet Plug-Ins");
    return true;
  }
  // In tests, just look in the module directory (below).
#endif

  // The rest of the world expects plugins in the module directory.
  return base::PathService::Get(base::DIR_MODULE, result);
}

// Gets the path for bundled implementations of components. Note that these
// implementations should not be used if higher-versioned component-updated
// implementations are available in DIR_USER_DATA.
bool GetComponentDirectory(base::FilePath* result) {
#if defined(OS_MACOSX)
  // If called from Chrome, return the framework's Libraries directory.
  if (base::mac::AmIBundled()) {
    *result = chrome::GetFrameworkBundlePath();
    DCHECK(!result->empty());
    *result = result->Append("Libraries");
    return true;
  }
// In tests, just look in the module directory (below).
#endif

  // The rest of the world expects components in the module directory.
  return base::PathService::Get(base::DIR_MODULE, result);
}

#if defined(OS_WIN)
// Gets the Pepper Flash path if installed on the system.
bool GetSystemFlashFilename(base::FilePath* out_path) {
  const wchar_t kPepperFlashRegistryRoot[] =
      L"SOFTWARE\\Macromedia\\FlashPlayerPepper";
  const wchar_t kFlashPlayerPathValueName[] = L"PlayerPath";

  base::win::RegKey path_key(HKEY_LOCAL_MACHINE, kPepperFlashRegistryRoot,
                             KEY_READ);
  base::string16 path_str;
  if (FAILED(path_key.ReadValue(kFlashPlayerPathValueName, &path_str)))
    return false;

  *out_path = base::FilePath(path_str);
  return true;
}
#endif

}  // namespace

namespace chrome {

bool PathProvider(int key, base::FilePath* result) {
  // Some keys are just aliases...
  switch (key) {
    case chrome::DIR_APP:
      return base::PathService::Get(base::DIR_MODULE, result);
    case chrome::DIR_LOGS:
#ifdef NDEBUG
      // Release builds write to the data dir
      return base::PathService::Get(chrome::DIR_USER_DATA, result);
#else
      // Debug builds write next to the binary (in the build tree)
#if defined(OS_MACOSX)
      // Apps may not write into their own bundle.
      if (base::mac::AmIBundled()) {
        return base::PathService::Get(chrome::DIR_USER_DATA, result);
      }
      return base::PathService::Get(base::DIR_EXE, result);
#else
      return base::PathService::Get(base::DIR_EXE, result);
#endif  // defined(OS_MACOSX)
#endif  // NDEBUG
    case chrome::FILE_RESOURCE_MODULE:
      return base::PathService::Get(base::FILE_MODULE, result);
  }

  // Assume that we will not need to create the directory if it does not exist.
  // This flag can be set to true for the cases where we want to create it.
  bool create_dir = false;

  base::FilePath cur;
  switch (key) {
    case chrome::DIR_USER_DATA:
      if (!GetDefaultUserDataDirectory(&cur)) {
        NOTREACHED();
        return false;
      }
      create_dir = true;
      break;
    case chrome::DIR_USER_DOCUMENTS:
      if (!GetUserDocumentsDirectory(&cur))
        return false;
      create_dir = true;
      break;
    case chrome::DIR_USER_MUSIC:
      if (!GetUserMusicDirectory(&cur))
        return false;
      break;
    case chrome::DIR_USER_PICTURES:
      if (!GetUserPicturesDirectory(&cur))
        return false;
      break;
    case chrome::DIR_USER_VIDEOS:
      if (!GetUserVideosDirectory(&cur))
        return false;
      break;
    case chrome::DIR_DEFAULT_DOWNLOADS_SAFE:
#if defined(OS_WIN) || defined(OS_LINUX)
      if (!GetUserDownloadsDirectorySafe(&cur))
        return false;
      break;
#else
      // Fall through for all other platforms.
#endif
    case chrome::DIR_DEFAULT_DOWNLOADS:
#if defined(OS_ANDROID)
      if (!base::android::GetDownloadsDirectory(&cur))
        return false;
#else
      if (!GetUserDownloadsDirectory(&cur))
        return false;
      // Do not create the download directory here, we have done it twice now
      // and annoyed a lot of users.
#endif
      break;
    case chrome::DIR_CRASH_DUMPS:
#if defined(OS_CHROMEOS)
      // ChromeOS uses a separate directory. See http://crosbug.com/25089
      cur = base::FilePath("/var/log/chrome");
#elif defined(OS_ANDROID)
      if (!base::android::GetCacheDirectory(&cur))
        return false;
#else
      // The crash reports are always stored relative to the default user data
      // directory.  This avoids the problem of having to re-initialize the
      // exception handler after parsing command line options, which may
      // override the location of the app's profile directory.
      // TODO(scottmg): Consider supporting --user-data-dir. See
      // https://crbug.com/565446.
      if (!GetDefaultUserDataDirectory(&cur))
        return false;
#endif
#if defined(OS_MACOSX) || defined(OS_WIN) || defined(OS_ANDROID)
      cur = cur.Append(FILE_PATH_LITERAL("Crashpad"));
#else
      cur = cur.Append(FILE_PATH_LITERAL("Crash Reports"));
#endif
      create_dir = true;
      break;
#if defined(OS_WIN)
    case chrome::DIR_WATCHER_DATA:
      // The watcher data is always stored relative to the default user data
      // directory.  This allows the watcher to be initialized before
      // command-line options have been parsed.
      if (!GetDefaultUserDataDirectory(&cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("Diagnostics"));
      break;
    case chrome::DIR_ROAMING_USER_DATA:
      if (!GetDefaultRoamingUserDataDirectory(&cur)) {
        NOTREACHED();
        return false;
      }
      create_dir = true;
      break;
#endif
    case chrome::DIR_RESOURCES:
#if defined(OS_MACOSX)
      cur = base::mac::FrameworkBundlePath();
      cur = cur.Append(FILE_PATH_LITERAL("Resources"));
#else
      if (!base::PathService::Get(chrome::DIR_APP, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("resources"));
#endif
      break;
    case chrome::DIR_INSPECTOR_DEBUG:
      if (!base::PathService::Get(chrome::DIR_RESOURCES, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("inspector"))
               .Append(FILE_PATH_LITERAL("debug"));
      break;
    case chrome::DIR_APP_DICTIONARIES:
#if defined(OS_POSIX)
      // We can't write into the EXE dir on Linux, so keep dictionaries
      // alongside the safe browsing database in the user data dir.
      // And we don't want to write into the bundle on the Mac, so push
      // it to the user data dir there also.
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
#else
      if (!base::PathService::Get(base::DIR_EXE, &cur))
        return false;
#endif
      cur = cur.Append(FILE_PATH_LITERAL("Dictionaries"));
      create_dir = true;
      break;
    case chrome::DIR_INTERNAL_PLUGINS:
      if (!GetInternalPluginsDirectory(&cur))
        return false;
      break;
    case chrome::DIR_COMPONENTS:
      if (!GetComponentDirectory(&cur))
        return false;
      break;
    case chrome::DIR_PEPPER_FLASH_PLUGIN:
      if (!GetInternalPluginsDirectory(&cur))
        return false;
      cur = cur.Append(kPepperFlashBaseDirectory);
      break;
    case chrome::DIR_COMPONENT_UPDATED_PEPPER_FLASH_PLUGIN:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(kPepperFlashBaseDirectory);
      break;
    case chrome::FILE_PEPPER_FLASH_SYSTEM_PLUGIN:
#if defined(OS_WIN)
      if (!GetSystemFlashFilename(&cur))
        return false;
#elif defined(OS_MACOSX)
      if (!GetLocalLibraryDirectory(&cur))
        return false;
      cur = cur.Append(kPepperFlashSystemBaseDirectory);
      cur = cur.Append(chrome::kPepperFlashPluginFilename);
#else
      // Chrome on iOS does not supports PPAPI binaries, return false.
      // TODO(wfh): If Adobe release PPAPI binaries for Linux, add support here.
      return false;
#endif
      break;
    case chrome::FILE_LOCAL_STATE:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(chrome::kLocalStateFilename);
      break;
    case chrome::FILE_RECORDED_SCRIPT:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("script.log"));
      break;
    case chrome::FILE_PEPPER_FLASH_PLUGIN:
      if (!base::PathService::Get(chrome::DIR_PEPPER_FLASH_PLUGIN, &cur))
        return false;
      cur = cur.Append(chrome::kPepperFlashPluginFilename);
      break;
    // PNaCl is currenly installable via the component updater or by being
    // simply built-in.  DIR_PNACL_BASE is used as the base directory for
    // installation via component updater.  DIR_PNACL_COMPONENT will be
    // the final location of pnacl, which is a subdir of DIR_PNACL_BASE.
    case chrome::DIR_PNACL_BASE:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("pnacl"));
      break;
    // Where PNaCl files are ultimately located.  The default finds the files
    // inside the InternalPluginsDirectory / build directory, as if it
    // was shipped along with chrome.  The value can be overridden
    // if it is installed via component updater.
    case chrome::DIR_PNACL_COMPONENT:
#if defined(OS_MACOSX)
      // PNaCl really belongs in the InternalPluginsDirectory but actually
      // copying it there would result in the files also being shipped, which
      // we don't want yet. So for now, just find them in the directory where
      // they get built.
      if (!base::PathService::Get(base::DIR_EXE, &cur))
        return false;
      if (base::mac::AmIBundled()) {
        // If we're called from chrome, it's beside the app (outside the
        // app bundle), if we're called from a unittest, we'll already be
        // outside the bundle so use the exe dir.
        // exe_dir gave us .../Chromium.app/Contents/MacOS/Chromium.
        cur = cur.DirName();
        cur = cur.DirName();
        cur = cur.DirName();
      }
#else
      if (!GetInternalPluginsDirectory(&cur))
        return false;
#endif
      cur = cur.Append(FILE_PATH_LITERAL("pnacl"));
      break;
#if BUILDFLAG(ENABLE_WIDEVINE) && BUILDFLAG(ENABLE_LIBRARY_CDMS)
    // TODO(crbug.com/663554): Remove this after component updated CDM is
    // supported on Linux and ChromeOS.
    case chrome::FILE_WIDEVINE_CDM:
      if (!GetComponentDirectory(&cur))
        return false;
      cur =
          cur.Append(
                 media::GetPlatformSpecificDirectory(kWidevineCdmBaseDirectory))
              .AppendASCII(base::GetNativeLibraryName(kWidevineCdmLibraryName));
      break;
#endif  // BUILDFLAG(ENABLE_WIDEVINE) && BUILDFLAG(ENABLE_LIBRARY_CDMS)
    case chrome::FILE_RESOURCES_PACK:  // Falls through.
    case chrome::FILE_DEV_UI_RESOURCES_PACK:
#if defined(OS_MACOSX)
      cur = base::mac::FrameworkBundlePath();
      cur = cur.Append(FILE_PATH_LITERAL("Resources"))
               .Append(FILE_PATH_LITERAL("resources.pak"));
      break;
#elif defined(OS_ANDROID)
      if (!base::PathService::Get(ui::DIR_RESOURCE_PAKS_ANDROID, &cur))
        return false;
      if (key == chrome::FILE_DEV_UI_RESOURCES_PACK) {
        cur = cur.Append(FILE_PATH_LITERAL("dev_ui_resources.pak"));
      } else {
        DCHECK_EQ(chrome::FILE_RESOURCES_PACK, key);
        cur = cur.Append(FILE_PATH_LITERAL("resources.pak"));
      }
#else
      // If we're not bundled on mac or Android, resources.pak should be next
      // to the binary (e.g., for unit tests).
      if (!base::PathService::Get(base::DIR_MODULE, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("resources.pak"));
#endif
      break;

#if defined(OS_CHROMEOS)
    case chrome::DIR_CHROMEOS_WALLPAPERS:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("wallpapers"));
      break;
    case chrome::DIR_CHROMEOS_WALLPAPER_THUMBNAILS:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("wallpaper_thumbnails"));
      break;
    case chrome::DIR_CHROMEOS_CUSTOM_WALLPAPERS:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("custom_wallpapers"));
      break;
    case chrome::FILE_CHROMEOS_CROSTINI_ANSIBLE_SOFTWARE_CONFIG:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("ansible_software_config.json"));
      break;
    case chrome::DIR_CHROMEOS_CROSTINI_ANSIBLE_PLAYBOOK_STAGING:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("ansible_playbook_staging"));
      create_dir = true;
      break;
#endif
#if BUILDFLAG(ENABLE_SUPERVISED_USERS)
    case chrome::DIR_SUPERVISED_USER_INSTALLED_WHITELISTS:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("SupervisedUserInstalledWhitelists"));
      break;
#endif
    // The following are only valid in the development environment, and
    // will fail if executed from an installed executable (because the
    // generated path won't exist).
    case chrome::DIR_GEN_TEST_DATA:
#if defined(OS_ANDROID)
      // On Android, our tests don't have permission to write to DIR_MODULE.
      // gtest/test_runner.py pushes data to external storage.
      if (!base::PathService::Get(base::DIR_SOURCE_ROOT, &cur))
        return false;
#else
      if (!base::PathService::Get(base::DIR_MODULE, &cur))
        return false;
#endif
      cur = cur.Append(FILE_PATH_LITERAL("test_data"));
      if (!base::PathExists(cur))  // We don't want to create this.
        return false;
      break;
    case chrome::DIR_TEST_DATA:
      if (!base::PathService::Get(base::DIR_SOURCE_ROOT, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("chrome"));
      cur = cur.Append(FILE_PATH_LITERAL("test"));
      cur = cur.Append(FILE_PATH_LITERAL("data"));
      if (!base::PathExists(cur))  // We don't want to create this.
        return false;
      break;
    case chrome::DIR_TEST_TOOLS:
      if (!base::PathService::Get(base::DIR_SOURCE_ROOT, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("chrome"));
      cur = cur.Append(FILE_PATH_LITERAL("tools"));
      cur = cur.Append(FILE_PATH_LITERAL("test"));
      if (!base::PathExists(cur))  // We don't want to create this
        return false;
      break;
#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_OPENBSD)
    case chrome::DIR_POLICY_FILES: {
#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
      cur = base::FilePath(FILE_PATH_LITERAL("/etc/opt/chrome/policies"));
#else
      cur = base::FilePath(FILE_PATH_LITERAL("/etc/chromium/policies"));
#endif
      break;
    }
#endif
#if defined(OS_CHROMEOS) || \
    (defined(OS_LINUX) && BUILDFLAG(CHROMIUM_BRANDING)) || defined(OS_MACOSX)
    case chrome::DIR_USER_EXTERNAL_EXTENSIONS: {
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("External Extensions"));
      break;
    }
#endif
#if defined(OS_LINUX)
    case chrome::DIR_STANDALONE_EXTERNAL_EXTENSIONS: {
      cur = base::FilePath(kFilepathSinglePrefExtensions);
      break;
    }
#endif
    case chrome::DIR_EXTERNAL_EXTENSIONS:
#if defined(OS_MACOSX)
      if (!chrome::GetGlobalApplicationSupportDirectory(&cur))
        return false;

      cur = cur.Append(FILE_PATH_LITERAL("Google"))
               .Append(FILE_PATH_LITERAL("Chrome"))
               .Append(FILE_PATH_LITERAL("External Extensions"));
      create_dir = false;
#else
      if (!base::PathService::Get(base::DIR_MODULE, &cur))
        return false;

      cur = cur.Append(FILE_PATH_LITERAL("extensions"));
      create_dir = true;
#endif
      break;

    case chrome::DIR_DEFAULT_APPS:
#if defined(OS_MACOSX)
      cur = base::mac::FrameworkBundlePath();
      cur = cur.Append(FILE_PATH_LITERAL("Default Apps"));
#else
      if (!base::PathService::Get(chrome::DIR_APP, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("default_apps"));
#endif
      break;

#if defined(OS_LINUX) || defined(OS_MACOSX)
    case chrome::DIR_NATIVE_MESSAGING:
#if defined(OS_MACOSX)
#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
      cur = base::FilePath(FILE_PATH_LITERAL(
           "/Library/Google/Chrome/NativeMessagingHosts"));
#else
      cur = base::FilePath(FILE_PATH_LITERAL(
          "/Library/Application Support/Chromium/NativeMessagingHosts"));
#endif
#else  // defined(OS_MACOSX)
#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
      cur = base::FilePath(FILE_PATH_LITERAL(
          "/etc/opt/chrome/native-messaging-hosts"));
#else
      cur = base::FilePath(FILE_PATH_LITERAL(
          "/etc/chromium/native-messaging-hosts"));
#endif
#endif  // !defined(OS_MACOSX)
      break;

    case chrome::DIR_USER_NATIVE_MESSAGING:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(FILE_PATH_LITERAL("NativeMessagingHosts"));
      break;
#endif  // defined(OS_LINUX) || defined(OS_MACOSX)
#if !defined(OS_ANDROID)
    case chrome::DIR_GLOBAL_GCM_STORE:
      if (!base::PathService::Get(chrome::DIR_USER_DATA, &cur))
        return false;
      cur = cur.Append(kGCMStoreDirname);
      break;
#endif  // !defined(OS_ANDROID)
#if defined(OS_LINUX)
    case chrome::FILE_COMPONENT_FLASH_HINT:
      if (!base::PathService::Get(
              chrome::DIR_COMPONENT_UPDATED_PEPPER_FLASH_PLUGIN, &cur)) {
        return false;
      }
      cur = cur.Append(kComponentUpdatedFlashHint);
      break;
#endif  // defined(OS_LINUX)
#if defined(OS_CHROMEOS)
    case chrome::FILE_CHROME_OS_COMPONENT_FLASH:
      cur = base::FilePath(kChromeOSComponentFlash);
      create_dir = false;
      break;
    case chrome::FILE_CHROME_OS_TPM_FIRMWARE_UPDATE_LOCATION:
      cur = base::FilePath(kChromeOSTPMFirmwareUpdateLocation);
      create_dir = false;
      break;
    case chrome::FILE_CHROME_OS_TPM_FIRMWARE_UPDATE_SRK_VULNERABLE_ROCA:
      cur = base::FilePath(kChromeOSTPMFirmwareUpdateSRKVulnerableROCA);
      create_dir = false;
      break;
#endif  // defined(OS_CHROMEOS)

    default:
      return false;
  }

  // TODO(bauerb): http://crbug.com/259796
  base::ThreadRestrictions::ScopedAllowIO allow_io;
  if (create_dir && !base::PathExists(cur) &&
      !base::CreateDirectory(cur))
    return false;

  *result = cur;
  return true;
}

// This cannot be done as a static initializer sadly since Visual Studio will
// eliminate this object file if there is no direct entry point into it.
void RegisterPathProvider() {
  base::PathService::RegisterProvider(PathProvider, PATH_START, PATH_END);
}

void SetInvalidSpecifiedUserDataDir(const base::FilePath& user_data_dir) {
  GetInvalidSpecifiedUserDataDirInternal() = user_data_dir;
}

const base::FilePath& GetInvalidSpecifiedUserDataDir() {
  return GetInvalidSpecifiedUserDataDirInternal();
}

}  // namespace chrome