extensions/common/manifest_handlers/background_info.cc - chromium/src - Git at Google

 // Copyright 2013 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "extensions/common/manifest_handlers/background_info.h"

 #include <stddef.h>

 #include <memory>

 #include "base/command_line.h"
 #include "base/feature_list.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/lazy_instance.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/error_utils.h"
 #include "extensions/common/file_util.h"
 #include "extensions/common/manifest_constants.h"
 #include "extensions/common/manifest_handlers/permissions_parser.h"
 #include "extensions/common/permissions/api_permission_set.h"
 #include "extensions/common/switches.h"
 #include "extensions/strings/grit/extensions_strings.h"
 #include "net/base/mime_util.h"
 #include "third_party/blink/public/common/mime_util/mime_util.h"
 #include "ui/base/l10n/l10n_util.h"

 using extensions::mojom::APIPermissionID;

 namespace extensions {

 namespace keys = manifest_keys;
 namespace values = manifest_values;
 namespace errors = manifest_errors;

 namespace {

 BASE_FEATURE(kValidateBackgroundScriptMimeType,
              "ValidateBackgroundScriptMimeType",
              base::FEATURE_ENABLED_BY_DEFAULT);

 const char kBackground[] = "background";

 static base::LazyInstance<BackgroundInfo>::DestructorAtExit
     g_empty_background_info = LAZY_INSTANCE_INITIALIZER;

 const BackgroundInfo& GetBackgroundInfo(const Extension* extension) {
   BackgroundInfo* info = static_cast<BackgroundInfo*>(
       extension->GetManifestData(kBackground));
   if (!info) {
     return g_empty_background_info.Get();
   }
   return *info;
 }

 }  // namespace

 BackgroundInfo::BackgroundInfo()
     : is_persistent_(true),
       allow_js_access_(true) {
 }

 BackgroundInfo::~BackgroundInfo() = default;

 // static
 GURL BackgroundInfo::GetBackgroundURL(const Extension* extension) {
   const BackgroundInfo& info = GetBackgroundInfo(extension);
   if (info.background_scripts_.empty()) {
     return info.background_url_;
   }
   return extension->GetResourceURL(kGeneratedBackgroundPageFilename);
 }

 // static
 const std::string& BackgroundInfo::GetBackgroundServiceWorkerScript(
     const Extension* extension) {
   const BackgroundInfo& info = GetBackgroundInfo(extension);
   DCHECK(info.background_service_worker_script_.has_value());
   return *info.background_service_worker_script_;
 }

 // static
 BackgroundServiceWorkerType BackgroundInfo::GetBackgroundServiceWorkerType(
     const Extension* extension) {
   const BackgroundInfo& info = GetBackgroundInfo(extension);
   return *info.background_service_worker_type_;
 }

 // static
 const std::vector<std::string>& BackgroundInfo::GetBackgroundScripts(
     const Extension* extension) {
   return GetBackgroundInfo(extension).background_scripts_;
 }

 // static
 bool BackgroundInfo::HasBackgroundPage(const Extension* extension) {
   return GetBackgroundInfo(extension).has_background_page();
 }

 // static
 bool BackgroundInfo::HasPersistentBackgroundPage(const Extension* extension)  {
   return GetBackgroundInfo(extension).has_persistent_background_page();
 }

 // static
 bool BackgroundInfo::HasLazyBackgroundPage(const Extension* extension) {
   return GetBackgroundInfo(extension).has_lazy_background_page();
 }

 // static
 bool BackgroundInfo::HasGeneratedBackgroundPage(const Extension* extension) {
   const BackgroundInfo& info = GetBackgroundInfo(extension);
   return !info.background_scripts_.empty();
 }

 // static
 bool BackgroundInfo::AllowJSAccess(const Extension* extension) {
   return GetBackgroundInfo(extension).allow_js_access_;
 }

 // static
 bool BackgroundInfo::IsServiceWorkerBased(const Extension* extension) {
   return GetBackgroundInfo(extension)
       .background_service_worker_script_.has_value();
 }

 bool BackgroundInfo::Parse(Extension* extension, std::u16string* error) {
   const std::string& bg_scripts_key = extension->is_platform_app() ?
       keys::kPlatformAppBackgroundScripts : keys::kBackgroundScripts;
   if (!LoadBackgroundScripts(extension, bg_scripts_key, error) ||
       !LoadBackgroundPage(extension, error) ||
       !LoadBackgroundServiceWorkerScript(extension, error) ||
       !LoadBackgroundPersistent(extension, error) ||
       !LoadAllowJSAccess(extension, error)) {
     return false;
   }

   int background_solution_sum =
       (background_url_.is_valid() ? 1 : 0) +
       (!background_scripts_.empty() ? 1 : 0) +
       (background_service_worker_script_.has_value() ? 1 : 0);
   if (background_solution_sum > 1) {
     *error = errors::kInvalidBackgroundCombination;
     return false;
   }

   return true;
 }

 bool BackgroundInfo::LoadBackgroundScripts(Extension* extension,
                                            const std::string& key,
                                            std::u16string* error) {
   const base::Value* background_scripts_value =
       extension->manifest()->FindPath(key);
   if (background_scripts_value == nullptr) {
     return true;
   }

   CHECK(background_scripts_value);
   if (!background_scripts_value->is_list()) {
     *error = errors::kInvalidBackgroundScripts;
     return false;
   }

   const base::Value::List& background_scripts =
       background_scripts_value->GetList();
   for (size_t i = 0; i < background_scripts.size(); ++i) {
     if (!background_scripts[i].is_string()) {
       *error = ErrorUtils::FormatErrorMessageUTF16(
           errors::kInvalidBackgroundScript, base::NumberToString(i));
       return false;
     }

     const std::string& background_script = background_scripts[i].GetString();

     std::string mime_type;
     // TODO(https://crbug.com/40059598): Remove this if-check and always
     // validate the mime type in M139.
     if (base::FeatureList::IsEnabled(kValidateBackgroundScriptMimeType) &&
         (!net::GetWellKnownMimeTypeFromFile(
              base::FilePath::FromUTF8Unsafe(background_script), &mime_type) ||
          !blink::IsSupportedJavascriptMimeType(mime_type))) {
       // Issue a warning and ignore this file. This is a warning and not a
       // hard-error to preserve both backwards compatibility and potential
       // future-compatibility if mime types change.
       extension->AddInstallWarning(
           InstallWarning(ErrorUtils::FormatErrorMessage(
                              errors::kInvalidBackgroundScriptMimeType,
                              base::NumberToString(i)),
                          key));
       continue;
     }

     background_scripts_.push_back(background_script);
   }

   return true;
 }

 bool BackgroundInfo::LoadBackgroundPage(const Extension* extension,
                                         const std::string& key,
                                         std::u16string* error) {
   const base::Value* background_page_value =
       extension->manifest()->FindPath(key);
   if (background_page_value == nullptr) {
     return true;
   }

   if (!background_page_value->is_string()) {
     *error = errors::kInvalidBackground;
     return false;
   }
   const std::string& background_str = background_page_value->GetString();

   if (extension->is_hosted_app()) {
     background_url_ = GURL(background_str);

     if (!PermissionsParser::HasAPIPermission(extension,
                                              APIPermissionID::kBackground)) {
       *error = errors::kBackgroundPermissionNeeded;
       return false;
     }
     // Hosted apps require an absolute URL.
     if (!background_url_.is_valid()) {
       *error = errors::kInvalidBackgroundInHostedApp;
       return false;
     }

     if (!(background_url_.SchemeIs("https") ||
           (base::CommandLine::ForCurrentProcess()->HasSwitch(
                switches::kAllowHTTPBackgroundPage) &&
            background_url_.SchemeIs("http")))) {
       *error = errors::kInvalidBackgroundInHostedApp;
       return false;
     }
   } else {
     background_url_ = extension->GetResourceURL(background_str);
     if (!background_url_.is_valid()) {
       *error = errors::kInvalidBackground;
       return false;
     }
   }

   return true;
 }

 bool BackgroundInfo::LoadBackgroundServiceWorkerScript(
     const Extension* extension,
     std::u16string* error) {
   const base::Value* scripts_value =
       extension->manifest()->FindPath(keys::kBackgroundServiceWorkerScript);
   if (scripts_value == nullptr) {
     return true;
   }

   DCHECK(scripts_value);
   if (!scripts_value->is_string()) {
     *error = errors::kInvalidBackgroundServiceWorkerScript;
     return false;
   }

   background_service_worker_script_ = scripts_value->GetString();

   const base::Value* scripts_type =
       extension->manifest()->FindPath(keys::kBackgroundServiceWorkerType);
   if (scripts_type == nullptr) {
     background_service_worker_type_ = BackgroundServiceWorkerType::kClassic;
     return true;
   }

   DCHECK(scripts_type);
   if (!scripts_type->is_string()) {
     *error = errors::kInvalidBackgroundServiceWorkerType;
     return false;
   }

   const std::string& type = scripts_type->GetString();
   if (type == "classic") {
     background_service_worker_type_ = BackgroundServiceWorkerType::kClassic;
     return true;
   }

   if (type == "module") {
     background_service_worker_type_ = BackgroundServiceWorkerType::kModule;
     return true;
   }

   *error = errors::kInvalidBackgroundServiceWorkerType;
   return false;
 }

 bool BackgroundInfo::LoadBackgroundPage(const Extension* extension,
                                         std::u16string* error) {
   const char* key = extension->is_platform_app()
                         ? keys::kPlatformAppBackgroundPage
                         : keys::kBackgroundPage;
   return LoadBackgroundPage(extension, key, error);
 }

 bool BackgroundInfo::LoadBackgroundPersistent(const Extension* extension,
                                               std::u16string* error) {
   if (extension->is_platform_app()) {
     is_persistent_ = false;
     return true;
   }

   const base::Value* background_persistent =
       extension->manifest()->FindPath(keys::kBackgroundPersistent);
   if (background_persistent == nullptr) {
     return true;
   }

   if (!background_persistent->is_bool()) {
     *error = errors::kInvalidBackgroundPersistent;
     return false;
   }
   is_persistent_ = background_persistent->GetBool();

   if (!has_background_page()) {
     *error = errors::kInvalidBackgroundPersistentNoPage;
     return false;
   }

   return true;
 }

 bool BackgroundInfo::LoadAllowJSAccess(const Extension* extension,
                                        std::u16string* error) {
   const base::Value* allow_js_access =
       extension->manifest()->FindPath(keys::kBackgroundAllowJsAccess);
   if (allow_js_access == nullptr) {
     return true;
   }

   if (!allow_js_access->is_bool()) {
     *error = errors::kInvalidBackgroundAllowJsAccess;
     return false;
   }
   allow_js_access_ = allow_js_access->GetBool();
   return true;
 }

 BackgroundManifestHandler::BackgroundManifestHandler() = default;
 BackgroundManifestHandler::~BackgroundManifestHandler() = default;

 bool BackgroundManifestHandler::Parse(Extension* extension,
                                       std::u16string* error) {
   std::unique_ptr<BackgroundInfo> info(new BackgroundInfo);
   if (!info->Parse(extension, error)) {
     return false;
   }

   // Platform apps must have background pages.
   if (extension->is_platform_app() && !info->has_background_page()) {
     *error = errors::kBackgroundRequiredForPlatformApps;
     return false;
   }
   // Lazy background pages are incompatible with the webRequest API.
   if (info->has_lazy_background_page() &&
       PermissionsParser::HasAPIPermission(extension,
                                           APIPermissionID::kWebRequest)) {
     *error = errors::kWebRequestConflictsWithLazyBackground;
     return false;
   }

   if (!info->has_lazy_background_page() &&
       PermissionsParser::HasAPIPermission(
           extension, APIPermissionID::kTransientBackground)) {
     *error = errors::kTransientBackgroundConflictsWithPersistentBackground;
     return false;
   }

   extension->SetManifestData(kBackground, std::move(info));
   return true;
 }

 bool BackgroundManifestHandler::Validate(
     const Extension& extension,
     std::string* error,
     std::vector<InstallWarning>* warnings) const {
   // Validate that background scripts exist.
   const std::vector<std::string>& background_scripts =
       BackgroundInfo::GetBackgroundScripts(&extension);
   for (const auto& background_script : background_scripts) {
     if (!base::PathExists(
             extension.GetResource(background_script).GetFilePath())) {
       *error =
           l10n_util::GetStringFUTF8(IDS_EXTENSION_LOAD_BACKGROUND_SCRIPT_FAILED,
                                     base::UTF8ToUTF16(background_script));
       return false;
     }
   }

   if (BackgroundInfo::IsServiceWorkerBased(&extension)) {
     DCHECK(extension.is_extension() ||
            extension.is_chromeos_system_extension() ||
            extension.is_login_screen_extension());
     const std::string& background_service_worker_script =
         BackgroundInfo::GetBackgroundServiceWorkerScript(&extension);
     if (!base::PathExists(
             extension.GetResource(background_service_worker_script)
                 .GetFilePath())) {
       *error = l10n_util::GetStringFUTF8(
           IDS_EXTENSION_LOAD_BACKGROUND_SCRIPT_FAILED,
           base::UTF8ToUTF16(background_service_worker_script));
       return false;
     }
   }

   // Validate background page location, except for hosted apps, which should use
   // an external URL. Background page for hosted apps are verified when the
   // extension is created (in Extension::InitFromValue)
   if (BackgroundInfo::HasBackgroundPage(&extension) &&
       !extension.is_hosted_app() && background_scripts.empty()) {
     base::FilePath page_path = file_util::ExtensionURLToRelativeFilePath(
         BackgroundInfo::GetBackgroundURL(&extension));
     const base::FilePath path = extension.GetResource(page_path).GetFilePath();
     if (path.empty() || !base::PathExists(path)) {
       *error =
           l10n_util::GetStringFUTF8(IDS_EXTENSION_LOAD_BACKGROUND_PAGE_FAILED,
                                     page_path.LossyDisplayName());
       return false;
     }
   }

   if (extension.is_platform_app()) {
     const std::string manifest_key =
         std::string(keys::kPlatformAppBackground) + ".persistent";
     // Validate that packaged apps do not use a persistent background page.
     if (extension.manifest()->FindBoolPath(manifest_key).value_or(false)) {
       warnings->emplace_back(errors::kInvalidBackgroundPersistentInPlatformApp);
     }
   }

   return true;
 }

 bool BackgroundManifestHandler::AlwaysParseForType(Manifest::Type type) const {
   return type == Manifest::TYPE_PLATFORM_APP;
 }

 base::span<const char* const> BackgroundManifestHandler::Keys() const {
   static constexpr const char* kKeys[] = {keys::kBackgroundAllowJsAccess,
                                           keys::kBackgroundPage,
                                           keys::kBackgroundPersistent,
                                           keys::kBackgroundScripts,
                                           keys::kBackgroundServiceWorkerScript,
                                           keys::kBackgroundServiceWorkerType,
                                           keys::kPlatformAppBackgroundPage,
                                           keys::kPlatformAppBackgroundScripts};
   return kKeys;
 }

 }  // namespace extensions
	// Copyright 2013 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "extensions/common/manifest_handlers/background_info.h"

	#include <stddef.h>

	#include <memory>

	#include "base/command_line.h"
	#include "base/feature_list.h"
	#include "base/files/file_path.h"
	#include "base/files/file_util.h"
	#include "base/lazy_instance.h"
	#include "base/strings/string_number_conversions.h"
	#include "base/strings/utf_string_conversions.h"
	#include "extensions/common/constants.h"
	#include "extensions/common/error_utils.h"
	#include "extensions/common/file_util.h"
	#include "extensions/common/manifest_constants.h"
	#include "extensions/common/manifest_handlers/permissions_parser.h"
	#include "extensions/common/permissions/api_permission_set.h"
	#include "extensions/common/switches.h"
	#include "extensions/strings/grit/extensions_strings.h"
	#include "net/base/mime_util.h"
	#include "third_party/blink/public/common/mime_util/mime_util.h"
	#include "ui/base/l10n/l10n_util.h"

	using extensions::mojom::APIPermissionID;

	namespace extensions {

	namespace keys = manifest_keys;
	namespace values = manifest_values;
	namespace errors = manifest_errors;

	namespace {

	BASE_FEATURE(kValidateBackgroundScriptMimeType,
	"ValidateBackgroundScriptMimeType",
	base::FEATURE_ENABLED_BY_DEFAULT);

	const char kBackground[] = "background";

	static base::LazyInstance<BackgroundInfo>::DestructorAtExit
	g_empty_background_info = LAZY_INSTANCE_INITIALIZER;

	const BackgroundInfo& GetBackgroundInfo(const Extension* extension) {
	BackgroundInfo* info = static_cast<BackgroundInfo*>(
	extension->GetManifestData(kBackground));
	if (!info) {
	return g_empty_background_info.Get();
	}
	return *info;
	}

	} // namespace

	BackgroundInfo::BackgroundInfo()
	: is_persistent_(true),
	allow_js_access_(true) {
	}

	BackgroundInfo::~BackgroundInfo() = default;

	// static
	GURL BackgroundInfo::GetBackgroundURL(const Extension* extension) {
	const BackgroundInfo& info = GetBackgroundInfo(extension);
	if (info.background_scripts_.empty()) {
	return info.background_url_;
	}
	return extension->GetResourceURL(kGeneratedBackgroundPageFilename);
	}

	// static
	const std::string& BackgroundInfo::GetBackgroundServiceWorkerScript(
	const Extension* extension) {
	const BackgroundInfo& info = GetBackgroundInfo(extension);
	DCHECK(info.background_service_worker_script_.has_value());
	return *info.background_service_worker_script_;
	}

	// static
	BackgroundServiceWorkerType BackgroundInfo::GetBackgroundServiceWorkerType(
	const Extension* extension) {
	const BackgroundInfo& info = GetBackgroundInfo(extension);
	return *info.background_service_worker_type_;
	}

	// static
	const std::vector<std::string>& BackgroundInfo::GetBackgroundScripts(
	const Extension* extension) {
	return GetBackgroundInfo(extension).background_scripts_;
	}

	// static
	bool BackgroundInfo::HasBackgroundPage(const Extension* extension) {
	return GetBackgroundInfo(extension).has_background_page();
	}

	// static
	bool BackgroundInfo::HasPersistentBackgroundPage(const Extension* extension) {
	return GetBackgroundInfo(extension).has_persistent_background_page();
	}

	// static
	bool BackgroundInfo::HasLazyBackgroundPage(const Extension* extension) {
	return GetBackgroundInfo(extension).has_lazy_background_page();
	}

	// static
	bool BackgroundInfo::HasGeneratedBackgroundPage(const Extension* extension) {
	const BackgroundInfo& info = GetBackgroundInfo(extension);
	return !info.background_scripts_.empty();
	}

	// static
	bool BackgroundInfo::AllowJSAccess(const Extension* extension) {
	return GetBackgroundInfo(extension).allow_js_access_;
	}

	// static
	bool BackgroundInfo::IsServiceWorkerBased(const Extension* extension) {
	return GetBackgroundInfo(extension)
	.background_service_worker_script_.has_value();
	}

	bool BackgroundInfo::Parse(Extension* extension, std::u16string* error) {
	const std::string& bg_scripts_key = extension->is_platform_app() ?
	keys::kPlatformAppBackgroundScripts : keys::kBackgroundScripts;
	if (!LoadBackgroundScripts(extension, bg_scripts_key, error) \|\|
	!LoadBackgroundPage(extension, error) \|\|
	!LoadBackgroundServiceWorkerScript(extension, error) \|\|
	!LoadBackgroundPersistent(extension, error) \|\|
	!LoadAllowJSAccess(extension, error)) {
	return false;
	}

	int background_solution_sum =
	(background_url_.is_valid() ? 1 : 0) +
	(!background_scripts_.empty() ? 1 : 0) +
	(background_service_worker_script_.has_value() ? 1 : 0);
	if (background_solution_sum > 1) {
	*error = errors::kInvalidBackgroundCombination;
	return false;
	}

	return true;
	}

	bool BackgroundInfo::LoadBackgroundScripts(Extension* extension,
	const std::string& key,
	std::u16string* error) {
	const base::Value* background_scripts_value =
	extension->manifest()->FindPath(key);
	if (background_scripts_value == nullptr) {
	return true;
	}

	CHECK(background_scripts_value);
	if (!background_scripts_value->is_list()) {
	*error = errors::kInvalidBackgroundScripts;
	return false;
	}

	const base::Value::List& background_scripts =
	background_scripts_value->GetList();
	for (size_t i = 0; i < background_scripts.size(); ++i) {
	if (!background_scripts[i].is_string()) {
	*error = ErrorUtils::FormatErrorMessageUTF16(
	errors::kInvalidBackgroundScript, base::NumberToString(i));
	return false;
	}

	const std::string& background_script = background_scripts[i].GetString();

	std::string mime_type;
	// TODO(https://crbug.com/40059598): Remove this if-check and always
	// validate the mime type in M139.
	if (base::FeatureList::IsEnabled(kValidateBackgroundScriptMimeType) &&
	(!net::GetWellKnownMimeTypeFromFile(
	base::FilePath::FromUTF8Unsafe(background_script), &mime_type) \|\|
	!blink::IsSupportedJavascriptMimeType(mime_type))) {
	// Issue a warning and ignore this file. This is a warning and not a
	// hard-error to preserve both backwards compatibility and potential
	// future-compatibility if mime types change.
	extension->AddInstallWarning(
	InstallWarning(ErrorUtils::FormatErrorMessage(
	errors::kInvalidBackgroundScriptMimeType,
	base::NumberToString(i)),
	key));
	continue;
	}

	background_scripts_.push_back(background_script);
	}

	return true;
	}

	bool BackgroundInfo::LoadBackgroundPage(const Extension* extension,
	const std::string& key,
	std::u16string* error) {
	const base::Value* background_page_value =
	extension->manifest()->FindPath(key);
	if (background_page_value == nullptr) {
	return true;
	}

	if (!background_page_value->is_string()) {
	*error = errors::kInvalidBackground;
	return false;
	}
	const std::string& background_str = background_page_value->GetString();

	if (extension->is_hosted_app()) {
	background_url_ = GURL(background_str);

	if (!PermissionsParser::HasAPIPermission(extension,
	APIPermissionID::kBackground)) {
	*error = errors::kBackgroundPermissionNeeded;
	return false;
	}
	// Hosted apps require an absolute URL.
	if (!background_url_.is_valid()) {
	*error = errors::kInvalidBackgroundInHostedApp;
	return false;
	}

	if (!(background_url_.SchemeIs("https") \|\|
	(base::CommandLine::ForCurrentProcess()->HasSwitch(
	switches::kAllowHTTPBackgroundPage) &&
	background_url_.SchemeIs("http")))) {
	*error = errors::kInvalidBackgroundInHostedApp;
	return false;
	}
	} else {
	background_url_ = extension->GetResourceURL(background_str);
	if (!background_url_.is_valid()) {
	*error = errors::kInvalidBackground;
	return false;
	}
	}

	return true;
	}

	bool BackgroundInfo::LoadBackgroundServiceWorkerScript(
	const Extension* extension,
	std::u16string* error) {
	const base::Value* scripts_value =
	extension->manifest()->FindPath(keys::kBackgroundServiceWorkerScript);
	if (scripts_value == nullptr) {
	return true;
	}

	DCHECK(scripts_value);
	if (!scripts_value->is_string()) {
	*error = errors::kInvalidBackgroundServiceWorkerScript;
	return false;
	}

	background_service_worker_script_ = scripts_value->GetString();

	const base::Value* scripts_type =
	extension->manifest()->FindPath(keys::kBackgroundServiceWorkerType);
	if (scripts_type == nullptr) {
	background_service_worker_type_ = BackgroundServiceWorkerType::kClassic;
	return true;
	}

	DCHECK(scripts_type);
	if (!scripts_type->is_string()) {
	*error = errors::kInvalidBackgroundServiceWorkerType;
	return false;
	}

	const std::string& type = scripts_type->GetString();
	if (type == "classic") {
	background_service_worker_type_ = BackgroundServiceWorkerType::kClassic;
	return true;
	}

	if (type == "module") {
	background_service_worker_type_ = BackgroundServiceWorkerType::kModule;
	return true;
	}

	*error = errors::kInvalidBackgroundServiceWorkerType;
	return false;
	}

	bool BackgroundInfo::LoadBackgroundPage(const Extension* extension,
	std::u16string* error) {
	const char* key = extension->is_platform_app()
	? keys::kPlatformAppBackgroundPage
	: keys::kBackgroundPage;
	return LoadBackgroundPage(extension, key, error);
	}

	bool BackgroundInfo::LoadBackgroundPersistent(const Extension* extension,
	std::u16string* error) {
	if (extension->is_platform_app()) {
	is_persistent_ = false;
	return true;
	}

	const base::Value* background_persistent =
	extension->manifest()->FindPath(keys::kBackgroundPersistent);
	if (background_persistent == nullptr) {
	return true;
	}

	if (!background_persistent->is_bool()) {
	*error = errors::kInvalidBackgroundPersistent;
	return false;
	}
	is_persistent_ = background_persistent->GetBool();

	if (!has_background_page()) {
	*error = errors::kInvalidBackgroundPersistentNoPage;
	return false;
	}

	return true;
	}

	bool BackgroundInfo::LoadAllowJSAccess(const Extension* extension,
	std::u16string* error) {
	const base::Value* allow_js_access =
	extension->manifest()->FindPath(keys::kBackgroundAllowJsAccess);
	if (allow_js_access == nullptr) {
	return true;
	}

	if (!allow_js_access->is_bool()) {
	*error = errors::kInvalidBackgroundAllowJsAccess;
	return false;
	}
	allow_js_access_ = allow_js_access->GetBool();
	return true;
	}

	BackgroundManifestHandler::BackgroundManifestHandler() = default;
	BackgroundManifestHandler::~BackgroundManifestHandler() = default;

	bool BackgroundManifestHandler::Parse(Extension* extension,
	std::u16string* error) {
	std::unique_ptr<BackgroundInfo> info(new BackgroundInfo);
	if (!info->Parse(extension, error)) {
	return false;
	}

	// Platform apps must have background pages.
	if (extension->is_platform_app() && !info->has_background_page()) {
	*error = errors::kBackgroundRequiredForPlatformApps;
	return false;
	}
	// Lazy background pages are incompatible with the webRequest API.
	if (info->has_lazy_background_page() &&
	PermissionsParser::HasAPIPermission(extension,
	APIPermissionID::kWebRequest)) {
	*error = errors::kWebRequestConflictsWithLazyBackground;
	return false;
	}

	if (!info->has_lazy_background_page() &&
	PermissionsParser::HasAPIPermission(
	extension, APIPermissionID::kTransientBackground)) {
	*error = errors::kTransientBackgroundConflictsWithPersistentBackground;
	return false;
	}

	extension->SetManifestData(kBackground, std::move(info));
	return true;
	}

	bool BackgroundManifestHandler::Validate(
	const Extension& extension,
	std::string* error,
	std::vector<InstallWarning>* warnings) const {
	// Validate that background scripts exist.
	const std::vector<std::string>& background_scripts =
	BackgroundInfo::GetBackgroundScripts(&extension);
	for (const auto& background_script : background_scripts) {
	if (!base::PathExists(
	extension.GetResource(background_script).GetFilePath())) {
	*error =
	l10n_util::GetStringFUTF8(IDS_EXTENSION_LOAD_BACKGROUND_SCRIPT_FAILED,
	base::UTF8ToUTF16(background_script));
	return false;
	}
	}

	if (BackgroundInfo::IsServiceWorkerBased(&extension)) {
	DCHECK(extension.is_extension() \|\|
	extension.is_chromeos_system_extension() \|\|
	extension.is_login_screen_extension());
	const std::string& background_service_worker_script =
	BackgroundInfo::GetBackgroundServiceWorkerScript(&extension);
	if (!base::PathExists(
	extension.GetResource(background_service_worker_script)
	.GetFilePath())) {
	*error = l10n_util::GetStringFUTF8(
	IDS_EXTENSION_LOAD_BACKGROUND_SCRIPT_FAILED,
	base::UTF8ToUTF16(background_service_worker_script));
	return false;
	}
	}

	// Validate background page location, except for hosted apps, which should use
	// an external URL. Background page for hosted apps are verified when the
	// extension is created (in Extension::InitFromValue)
	if (BackgroundInfo::HasBackgroundPage(&extension) &&
	!extension.is_hosted_app() && background_scripts.empty()) {
	base::FilePath page_path = file_util::ExtensionURLToRelativeFilePath(
	BackgroundInfo::GetBackgroundURL(&extension));
	const base::FilePath path = extension.GetResource(page_path).GetFilePath();
	if (path.empty() \|\| !base::PathExists(path)) {
	*error =
	l10n_util::GetStringFUTF8(IDS_EXTENSION_LOAD_BACKGROUND_PAGE_FAILED,
	page_path.LossyDisplayName());
	return false;
	}
	}

	if (extension.is_platform_app()) {
	const std::string manifest_key =
	std::string(keys::kPlatformAppBackground) + ".persistent";
	// Validate that packaged apps do not use a persistent background page.
	if (extension.manifest()->FindBoolPath(manifest_key).value_or(false)) {
	warnings->emplace_back(errors::kInvalidBackgroundPersistentInPlatformApp);
	}
	}

	return true;
	}

	bool BackgroundManifestHandler::AlwaysParseForType(Manifest::Type type) const {
	return type == Manifest::TYPE_PLATFORM_APP;
	}

	base::span<const char* const> BackgroundManifestHandler::Keys() const {
	static constexpr const char* kKeys[] = {keys::kBackgroundAllowJsAccess,
	keys::kBackgroundPage,
	keys::kBackgroundPersistent,
	keys::kBackgroundScripts,
	keys::kBackgroundServiceWorkerScript,
	keys::kBackgroundServiceWorkerType,
	keys::kPlatformAppBackgroundPage,
	keys::kPlatformAppBackgroundScripts};
	return kKeys;
	}

	} // namespace extensions