extensions/common/file_util.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "extensions/common/file_util.h"
   6
   7 #include <map>
   8 #include <set>
   9 #include <string>
  10 #include <utility>
  11 #include <vector>
  12
  13 #include "base/files/file_enumerator.h"
  14 #include "base/files/file_path.h"
  15 #include "base/files/file_util.h"
  16 #include "base/files/scoped_temp_dir.h"
  17 #include "base/json/json_file_value_serializer.h"
  18 #include "base/logging.h"
  19 #include "base/memory/scoped_ptr.h"
  20 #include "base/metrics/field_trial.h"
  21 #include "base/metrics/histogram.h"
  22 #include "base/strings/stringprintf.h"
  23 #include "base/strings/utf_string_conversions.h"
  24 #include "base/threading/thread_restrictions.h"
  25 #include "base/time/time.h"
  26 #include "extensions/common/constants.h"
  27 #include "extensions/common/extension.h"
  28 #include "extensions/common/extension_icon_set.h"
  29 #include "extensions/common/extension_l10n_util.h"
  30 #include "extensions/common/extension_set.h"
  31 #include "extensions/common/install_warning.h"
  32 #include "extensions/common/manifest.h"
  33 #include "extensions/common/manifest_constants.h"
  34 #include "extensions/common/manifest_handler.h"
  35 #include "extensions/common/manifest_handlers/default_locale_handler.h"
  36 #include "extensions/common/manifest_handlers/icons_handler.h"
  37 #include "extensions/common/manifest_handlers/shared_module_info.h"
  38 #include "grit/extensions_strings.h"
  39 #include "net/base/escape.h"
  40 #include "net/base/filename_util.h"
  41 #include "ui/base/l10n/l10n_util.h"
  42 #include "url/gurl.h"
  43
  44 namespace extensions {
  45 namespace file_util {
  46 namespace {
  47
  48 // Returns true if the given file path exists and is not zero-length.
  49 bool ValidateFilePath(const base::FilePath& path) {
  50   int64 size = 0;
  51   if (!base::PathExists(path) ||
  52       !base::GetFileSize(path, &size) ||
  53       size == 0) {
  54     return false;
  55   }
  56
  57   return true;
  58 }
  59
  60 // Returns true if the extension installation should flush all files and the
  61 // directory.
  62 bool UseSafeInstallation() {
  63   const char kFieldTrialName[] = "ExtensionUseSafeInstallation";
  64   const char kEnable[] = "Enable";
  65   return base::FieldTrialList::FindFullName(kFieldTrialName) == kEnable;
  66 }
  67
  68 enum FlushOneOrAllFiles {
  69    ONE_FILE_ONLY,
  70    ALL_FILES
  71 };
  72
  73 // Flush all files in a directory or just one.  When flushing all files, it
  74 // makes sure every file is on disk.  When flushing one file only, it ensures
  75 // all parent directories are on disk.
  76 void FlushFilesInDir(const base::FilePath& path,
  77                      FlushOneOrAllFiles one_or_all_files) {
  78   if (!UseSafeInstallation()) {
  79     return;
  80   }
  81   base::FileEnumerator temp_traversal(path,
  82                                       true,  // recursive
  83                                       base::FileEnumerator::FILES);
  84   for (base::FilePath current = temp_traversal.Next(); !current.empty();
  85       current = temp_traversal.Next()) {
  86     base::File currentFile(current,
  87                            base::File::FLAG_OPEN | base::File::FLAG_WRITE);
  88     currentFile.Flush();
  89     currentFile.Close();
  90     if (one_or_all_files == ONE_FILE_ONLY) {
  91       break;
  92     }
  93   }
  94 }
  95
  96 }  // namespace
  97
  98 const base::FilePath::CharType kTempDirectoryName[] = FILE_PATH_LITERAL("Temp");
  99
 100 base::FilePath InstallExtension(const base::FilePath& unpacked_source_dir,
 101                                 const std::string& id,
 102                                 const std::string& version,
 103                                 const base::FilePath& extensions_dir) {
 104   base::FilePath extension_dir = extensions_dir.AppendASCII(id);
 105   base::FilePath version_dir;
 106
 107   // Create the extension directory if it doesn't exist already.
 108   if (!base::PathExists(extension_dir)) {
 109     if (!base::CreateDirectory(extension_dir))
 110       return base::FilePath();
 111   }
 112
 113   // Get a temp directory on the same file system as the profile.
 114   base::FilePath install_temp_dir = GetInstallTempDir(extensions_dir);
 115   base::ScopedTempDir extension_temp_dir;
 116   if (install_temp_dir.empty() ||
 117       !extension_temp_dir.CreateUniqueTempDirUnderPath(install_temp_dir)) {
 118     LOG(ERROR) << "Creating of temp dir under in the profile failed.";
 119     return base::FilePath();
 120   }
 121   base::FilePath crx_temp_source =
 122       extension_temp_dir.path().Append(unpacked_source_dir.BaseName());
 123   if (!base::Move(unpacked_source_dir, crx_temp_source)) {
 124     LOG(ERROR) << "Moving extension from : " << unpacked_source_dir.value()
 125                << " to : " << crx_temp_source.value() << " failed.";
 126     return base::FilePath();
 127   }
 128
 129   // Try to find a free directory. There can be legitimate conflicts in the case
 130   // of overinstallation of the same version.
 131   const int kMaxAttempts = 100;
 132   for (int i = 0; i < kMaxAttempts; ++i) {
 133     base::FilePath candidate = extension_dir.AppendASCII(
 134         base::StringPrintf("%s_%u", version.c_str(), i));
 135     if (!base::PathExists(candidate)) {
 136       version_dir = candidate;
 137       break;
 138     }
 139   }
 140
 141   if (version_dir.empty()) {
 142     LOG(ERROR) << "Could not find a home for extension " << id << " with "
 143                << "version " << version << ".";
 144     return base::FilePath();
 145   }
 146
 147   base::TimeTicks start_time = base::TimeTicks::Now();
 148
 149   // Flush the source dir completely before moving to make sure everything is
 150   // on disk. Otherwise a sudden power loss could cause the newly installed
 151   // extension to be in a corrupted state. Note that empty sub-directories
 152   // may still be lost.
 153   FlushFilesInDir(crx_temp_source, ALL_FILES);
 154
 155   // The target version_dir does not exists yet, so base::Move() is using
 156   // rename() on POSIX systems. It is atomic in the sense that it will
 157   // either complete successfully or in the event of data loss be reverted.
 158   if (!base::Move(crx_temp_source, version_dir)) {
 159     LOG(ERROR) << "Installing extension from : " << crx_temp_source.value()
 160                << " into : " << version_dir.value() << " failed.";
 161     return base::FilePath();
 162   }
 163
 164   // Flush one file in the new version_dir to make sure the dir move above is
 165   // persisted on disk. This is guaranteed on POSIX systems. ExtensionPrefs
 166   // is going to be updated with the new version_dir later. In the event of
 167   // data loss ExtensionPrefs should be pointing to the previous version which
 168   // is still fine.
 169   FlushFilesInDir(version_dir, ONE_FILE_ONLY);
 170
 171   UMA_HISTOGRAM_TIMES("Extensions.FileInstallation",
 172                       base::TimeTicks::Now() - start_time);
 173
 174   return version_dir;
 175 }
 176
 177 void UninstallExtension(const base::FilePath& extensions_dir,
 178                         const std::string& id) {
 179   // We don't care about the return value. If this fails (and it can, due to
 180   // plugins that aren't unloaded yet), it will get cleaned up by
 181   // ExtensionGarbageCollector::GarbageCollectExtensions.
 182   base::DeleteFile(extensions_dir.AppendASCII(id), true);  // recursive.
 183 }
 184
 185 scoped_refptr<Extension> LoadExtension(const base::FilePath& extension_path,
 186                                        Manifest::Location location,
 187                                        int flags,
 188                                        std::string* error) {
 189   return LoadExtension(extension_path, std::string(), location, flags, error);
 190 }
 191
 192 scoped_refptr<Extension> LoadExtension(const base::FilePath& extension_path,
 193                                        const std::string& extension_id,
 194                                        Manifest::Location location,
 195                                        int flags,
 196                                        std::string* error) {
 197   scoped_ptr<base::DictionaryValue> manifest(
 198       LoadManifest(extension_path, error));
 199   if (!manifest.get())
 200     return NULL;
 201   if (!extension_l10n_util::LocalizeExtension(
 202           extension_path, manifest.get(), error)) {
 203     return NULL;
 204   }
 205
 206   scoped_refptr<Extension> extension(Extension::Create(
 207       extension_path, location, *manifest, flags, extension_id, error));
 208   if (!extension.get())
 209     return NULL;
 210
 211   std::vector<InstallWarning> warnings;
 212   if (!ValidateExtension(extension.get(), error, &warnings))
 213     return NULL;
 214   extension->AddInstallWarnings(warnings);
 215
 216   return extension;
 217 }
 218
 219 base::DictionaryValue* LoadManifest(const base::FilePath& extension_path,
 220                                     std::string* error) {
 221   return LoadManifest(extension_path, kManifestFilename, error);
 222 }
 223
 224 base::DictionaryValue* LoadManifest(
 225     const base::FilePath& extension_path,
 226     const base::FilePath::CharType* manifest_filename,
 227     std::string* error) {
 228   base::FilePath manifest_path = extension_path.Append(manifest_filename);
 229   if (!base::PathExists(manifest_path)) {
 230     *error = l10n_util::GetStringUTF8(IDS_EXTENSION_MANIFEST_UNREADABLE);
 231     return NULL;
 232   }
 233
 234   JSONFileValueDeserializer deserializer(manifest_path);
 235   scoped_ptr<base::Value> root(deserializer.Deserialize(NULL, error));
 236   if (!root.get()) {
 237     if (error->empty()) {
 238       // If |error| is empty, than the file could not be read.
 239       // It would be cleaner to have the JSON reader give a specific error
 240       // in this case, but other code tests for a file error with
 241       // error->empty().  For now, be consistent.
 242       *error = l10n_util::GetStringUTF8(IDS_EXTENSION_MANIFEST_UNREADABLE);
 243     } else {
 244       *error = base::StringPrintf(
 245           "%s  %s", manifest_errors::kManifestParseError, error->c_str());
 246     }
 247     return NULL;
 248   }
 249
 250   if (!root->IsType(base::Value::TYPE_DICTIONARY)) {
 251     *error = l10n_util::GetStringUTF8(IDS_EXTENSION_MANIFEST_INVALID);
 252     return NULL;
 253   }
 254
 255   return static_cast<base::DictionaryValue*>(root.release());
 256 }
 257
 258 bool ValidateExtension(const Extension* extension,
 259                        std::string* error,
 260                        std::vector<InstallWarning>* warnings) {
 261   // Ask registered manifest handlers to validate their paths.
 262   if (!ManifestHandler::ValidateExtension(extension, error, warnings))
 263     return false;
 264
 265   // Check children of extension root to see if any of them start with _ and is
 266   // not on the reserved list. We only warn, and do not block the loading of the
 267   // extension.
 268   std::string warning;
 269   if (!CheckForIllegalFilenames(extension->path(), &warning))
 270     warnings->push_back(InstallWarning(warning));
 271
 272   // Check that the extension does not include any Windows reserved filenames.
 273   std::string windows_reserved_warning;
 274   if (!CheckForWindowsReservedFilenames(extension->path(),
 275                                         &windows_reserved_warning)) {
 276     warnings->push_back(InstallWarning(windows_reserved_warning));
 277   }
 278
 279   // Check that extensions don't include private key files.
 280   std::vector<base::FilePath> private_keys =
 281       FindPrivateKeyFiles(extension->path());
 282   if (extension->creation_flags() & Extension::ERROR_ON_PRIVATE_KEY) {
 283     if (!private_keys.empty()) {
 284       // Only print one of the private keys because l10n_util doesn't have a way
 285       // to translate a list of strings.
 286       *error =
 287           l10n_util::GetStringFUTF8(IDS_EXTENSION_CONTAINS_PRIVATE_KEY,
 288                                     private_keys.front().LossyDisplayName());
 289       return false;
 290     }
 291   } else {
 292     for (size_t i = 0; i < private_keys.size(); ++i) {
 293       warnings->push_back(InstallWarning(
 294           l10n_util::GetStringFUTF8(IDS_EXTENSION_CONTAINS_PRIVATE_KEY,
 295                                     private_keys[i].LossyDisplayName())));
 296     }
 297     // Only warn; don't block loading the extension.
 298   }
 299   return true;
 300 }
 301
 302 std::vector<base::FilePath> FindPrivateKeyFiles(
 303     const base::FilePath& extension_dir) {
 304   std::vector<base::FilePath> result;
 305   // Pattern matching only works at the root level, so filter manually.
 306   base::FileEnumerator traversal(
 307       extension_dir, /*recursive=*/true, base::FileEnumerator::FILES);
 308   for (base::FilePath current = traversal.Next(); !current.empty();
 309        current = traversal.Next()) {
 310     if (!current.MatchesExtension(kExtensionKeyFileExtension))
 311       continue;
 312
 313     std::string key_contents;
 314     if (!base::ReadFileToString(current, &key_contents)) {
 315       // If we can't read the file, assume it's not a private key.
 316       continue;
 317     }
 318     std::string key_bytes;
 319     if (!Extension::ParsePEMKeyBytes(key_contents, &key_bytes)) {
 320       // If we can't parse the key, assume it's ok too.
 321       continue;
 322     }
 323
 324     result.push_back(current);
 325   }
 326   return result;
 327 }
 328
 329 bool CheckForIllegalFilenames(const base::FilePath& extension_path,
 330                               std::string* error) {
 331   // Reserved underscore names.
 332   static const base::FilePath::CharType* reserved_names[] = {
 333       kLocaleFolder, kPlatformSpecificFolder, FILE_PATH_LITERAL("__MACOSX"), };
 334   CR_DEFINE_STATIC_LOCAL(
 335       std::set<base::FilePath::StringType>,
 336       reserved_underscore_names,
 337       (reserved_names, reserved_names + arraysize(reserved_names)));
 338
 339   // Enumerate all files and directories in the extension root.
 340   // There is a problem when using pattern "_*" with FileEnumerator, so we have
 341   // to cheat with find_first_of and match all.
 342   const int kFilesAndDirectories =
 343       base::FileEnumerator::DIRECTORIES | base::FileEnumerator::FILES;
 344   base::FileEnumerator all_files(extension_path, false, kFilesAndDirectories);
 345
 346   base::FilePath file;
 347   while (!(file = all_files.Next()).empty()) {
 348     base::FilePath::StringType filename = file.BaseName().value();
 349
 350     // Skip all that don't start with "_".
 351     if (filename.find_first_of(FILE_PATH_LITERAL("_")) != 0)
 352       continue;
 353     if (reserved_underscore_names.find(filename) ==
 354         reserved_underscore_names.end()) {
 355       *error = base::StringPrintf(
 356           "Cannot load extension with file or directory name %s. "
 357           "Filenames starting with \"_\" are reserved for use by the system.",
 358           file.BaseName().AsUTF8Unsafe().c_str());
 359       return false;
 360     }
 361   }
 362
 363   return true;
 364 }
 365
 366 bool CheckForWindowsReservedFilenames(const base::FilePath& extension_dir,
 367                                       std::string* error) {
 368   const int kFilesAndDirectories =
 369       base::FileEnumerator::DIRECTORIES | base::FileEnumerator::FILES;
 370   base::FileEnumerator traversal(extension_dir, true, kFilesAndDirectories);
 371
 372   for (base::FilePath current = traversal.Next(); !current.empty();
 373        current = traversal.Next()) {
 374     base::FilePath::StringType filename = current.BaseName().value();
 375     bool is_reserved_filename = net::IsReservedNameOnWindows(filename);
 376     if (is_reserved_filename) {
 377       *error = base::StringPrintf(
 378           "Cannot load extension with file or directory name %s. "
 379           "The filename is illegal.",
 380           current.BaseName().AsUTF8Unsafe().c_str());
 381       return false;
 382     }
 383   }
 384
 385   return true;
 386 }
 387
 388 base::FilePath GetInstallTempDir(const base::FilePath& extensions_dir) {
 389   // We do file IO in this function, but only when the current profile's
 390   // Temp directory has never been used before, or in a rare error case.
 391   // Developers are not likely to see these situations often, so do an
 392   // explicit thread check.
 393   base::ThreadRestrictions::AssertIOAllowed();
 394
 395   // Create the temp directory as a sub-directory of the Extensions directory.
 396   // This guarantees it is on the same file system as the extension's eventual
 397   // install target.
 398   base::FilePath temp_path = extensions_dir.Append(kTempDirectoryName);
 399   if (base::PathExists(temp_path)) {
 400     if (!base::DirectoryExists(temp_path)) {
 401       DLOG(WARNING) << "Not a directory: " << temp_path.value();
 402       return base::FilePath();
 403     }
 404     if (!base::PathIsWritable(temp_path)) {
 405       DLOG(WARNING) << "Can't write to path: " << temp_path.value();
 406       return base::FilePath();
 407     }
 408     // This is a directory we can write to.
 409     return temp_path;
 410   }
 411
 412   // Directory doesn't exist, so create it.
 413   if (!base::CreateDirectory(temp_path)) {
 414     DLOG(WARNING) << "Couldn't create directory: " << temp_path.value();
 415     return base::FilePath();
 416   }
 417   return temp_path;
 418 }
 419
 420 void DeleteFile(const base::FilePath& path, bool recursive) {
 421   base::DeleteFile(path, recursive);
 422 }
 423
 424 base::FilePath ExtensionURLToRelativeFilePath(const GURL& url) {
 425   std::string url_path = url.path();
 426   if (url_path.empty() || url_path[0] != '/')
 427     return base::FilePath();
 428
 429   // Drop the leading slashes and convert %-encoded UTF8 to regular UTF8.
 430   std::string file_path = net::UnescapeURLComponent(url_path,
 431       net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS);
 432   size_t skip = file_path.find_first_not_of("/\\");
 433   if (skip != file_path.npos)
 434     file_path = file_path.substr(skip);
 435
 436   base::FilePath path = base::FilePath::FromUTF8Unsafe(file_path);
 437
 438   // It's still possible for someone to construct an annoying URL whose path
 439   // would still wind up not being considered relative at this point.
 440   // For example: chrome-extension://id/c:////foo.html
 441   if (path.IsAbsolute())
 442     return base::FilePath();
 443
 444   return path;
 445 }
 446
 447 base::FilePath ExtensionResourceURLToFilePath(const GURL& url,
 448                                               const base::FilePath& root) {
 449   std::string host = net::UnescapeURLComponent(url.host(),
 450       net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS);
 451   if (host.empty())
 452     return base::FilePath();
 453
 454   base::FilePath relative_path = ExtensionURLToRelativeFilePath(url);
 455   if (relative_path.empty())
 456     return base::FilePath();
 457
 458   base::FilePath path = root.AppendASCII(host).Append(relative_path);
 459   if (!base::PathExists(path))
 460     return base::FilePath();
 461   path = base::MakeAbsoluteFilePath(path);
 462   if (path.empty() || !root.IsParent(path))
 463     return base::FilePath();
 464   return path;
 465 }
 466
 467 bool ValidateExtensionIconSet(const ExtensionIconSet& icon_set,
 468                               const Extension* extension,
 469                               int error_message_id,
 470                               std::string* error) {
 471   for (ExtensionIconSet::IconMap::const_iterator iter = icon_set.map().begin();
 472        iter != icon_set.map().end();
 473        ++iter) {
 474     const base::FilePath path =
 475         extension->GetResource(iter->second).GetFilePath();
 476     if (!ValidateFilePath(path)) {
 477       *error = l10n_util::GetStringFUTF8(error_message_id,
 478                                          base::UTF8ToUTF16(iter->second));
 479       return false;
 480     }
 481   }
 482   return true;
 483 }
 484
 485 MessageBundle* LoadMessageBundle(
 486     const base::FilePath& extension_path,
 487     const std::string& default_locale,
 488     std::string* error) {
 489   error->clear();
 490   // Load locale information if available.
 491   base::FilePath locale_path = extension_path.Append(kLocaleFolder);
 492   if (!base::PathExists(locale_path))
 493     return NULL;
 494
 495   std::set<std::string> chrome_locales;
 496   extension_l10n_util::GetAllLocales(&chrome_locales);
 497
 498   base::FilePath default_locale_path = locale_path.AppendASCII(default_locale);
 499   if (default_locale.empty() ||
 500       chrome_locales.find(default_locale) == chrome_locales.end() ||
 501       !base::PathExists(default_locale_path)) {
 502     *error = l10n_util::GetStringUTF8(
 503         IDS_EXTENSION_LOCALES_NO_DEFAULT_LOCALE_SPECIFIED);
 504     return NULL;
 505   }
 506
 507   MessageBundle* message_bundle =
 508       extension_l10n_util::LoadMessageCatalogs(
 509           locale_path,
 510           default_locale,
 511           extension_l10n_util::CurrentLocaleOrDefault(),
 512           error);
 513
 514   return message_bundle;
 515 }
 516
 517 MessageBundle::SubstitutionMap* LoadMessageBundleSubstitutionMap(
 518     const base::FilePath& extension_path,
 519     const std::string& extension_id,
 520     const std::string& default_locale) {
 521   MessageBundle::SubstitutionMap* return_value =
 522       new MessageBundle::SubstitutionMap();
 523   if (!default_locale.empty()) {
 524     // Touch disk only if extension is localized.
 525     std::string error;
 526     scoped_ptr<MessageBundle> bundle(
 527         LoadMessageBundle(extension_path, default_locale, &error));
 528
 529     if (bundle.get())
 530       *return_value = *bundle->dictionary();
 531   }
 532
 533   // Add @@extension_id reserved message here, so it's available to
 534   // non-localized extensions too.
 535   return_value->insert(
 536       std::make_pair(MessageBundle::kExtensionIdKey, extension_id));
 537
 538   return return_value;
 539 }
 540
 541 MessageBundle::SubstitutionMap* LoadMessageBundleSubstitutionMapWithImports(
 542     const std::string& extension_id,
 543     const ExtensionSet& extension_set) {
 544   const Extension* extension = extension_set.GetByID(extension_id);
 545   MessageBundle::SubstitutionMap* return_value =
 546       new MessageBundle::SubstitutionMap();
 547
 548   // Add @@extension_id reserved message here, so it's available to
 549   // non-localized extensions too.
 550   return_value->insert(
 551       std::make_pair(MessageBundle::kExtensionIdKey, extension_id));
 552
 553   base::FilePath extension_path;
 554   std::string default_locale;
 555   if (!extension) {
 556     NOTREACHED() << "Missing extension " << extension_id;
 557     return return_value;
 558   }
 559
 560   // Touch disk only if extension is localized.
 561   default_locale = LocaleInfo::GetDefaultLocale(extension);
 562   if (default_locale.empty()) {
 563     return return_value;
 564   }
 565
 566   std::string error;
 567   scoped_ptr<MessageBundle> bundle(
 568       LoadMessageBundle(extension->path(), default_locale, &error));
 569
 570   if (bundle.get()) {
 571     for (auto iter : *bundle->dictionary()) {
 572       return_value->insert(std::make_pair(iter.first, iter.second));
 573     }
 574   }
 575
 576   auto imports = extensions::SharedModuleInfo::GetImports(extension);
 577   // Iterate through the imports in reverse.  This will allow later imported
 578   // modules to override earlier imported modules, as the list order is
 579   // maintained from the definition in manifest.json of the imports.
 580   for (auto it = imports.rbegin(); it != imports.rend(); ++it) {
 581     const extensions::Extension* imported_extension =
 582         extension_set.GetByID(it->extension_id);
 583     if (!imported_extension) {
 584       NOTREACHED() << "Missing shared module " << it->extension_id;
 585       continue;
 586     }
 587     scoped_ptr<MessageBundle> imported_bundle(
 588         LoadMessageBundle(imported_extension->path(), default_locale, &error));
 589
 590     if (imported_bundle.get()) {
 591       for (auto iter : *imported_bundle->dictionary()) {
 592         // |insert| only adds new entries, and does not replace entries in
 593         // the main extension or previously processed imports.
 594         return_value->insert(std::make_pair(iter.first, iter.second));
 595       }
 596     }
 597   }
 598
 599   return return_value;
 600 }
 601
 602 base::FilePath GetVerifiedContentsPath(const base::FilePath& extension_path) {
 603   return extension_path.Append(kMetadataFolder)
 604       .Append(kVerifiedContentsFilename);
 605 }
 606 base::FilePath GetComputedHashesPath(const base::FilePath& extension_path) {
 607   return extension_path.Append(kMetadataFolder).Append(kComputedHashesFilename);
 608 }
 609
 610 }  // namespace file_util
 611 }  // namespace extensions