 Chromium Code Reviews
 Chromium Code Reviews Issue 2902653002:
  Get main frame and subframe AppCache loads to work.   (Closed)
    
  
    Issue 2902653002:
  Get main frame and subframe AppCache loads to work.   (Closed) 
  | Index: content/browser/appcache/appcache_url_loader_factory.cc | 
| diff --git a/content/browser/appcache/appcache_url_loader_factory.cc b/content/browser/appcache/appcache_url_loader_factory.cc | 
| index ce57fbdff08f2cc4c6bddbdfa806cb7b1d089f05..8a745362a207e00ee1a4755eed5e142c257e8652 100644 | 
| --- a/content/browser/appcache/appcache_url_loader_factory.cc | 
| +++ b/content/browser/appcache/appcache_url_loader_factory.cc | 
| @@ -6,13 +6,17 @@ | 
| #include "base/bind.h" | 
| #include "base/logging.h" | 
| -#include "content/browser/appcache/appcache_entry.h" | 
| -#include "content/browser/appcache/appcache_policy.h" | 
| +#include "content/browser/appcache/appcache_backend_impl.h" | 
| +#include "content/browser/appcache/appcache_host.h" | 
| +#include "content/browser/appcache/appcache_navigation_handle_core.h" | 
| #include "content/browser/appcache/appcache_request.h" | 
| +#include "content/browser/appcache/appcache_request_handler.h" | 
| #include "content/browser/appcache/appcache_storage.h" | 
| +#include "content/browser/appcache/appcache_url_loader_job.h" | 
| +#include "content/browser/appcache/appcache_url_loader_request.h" | 
| #include "content/browser/appcache/chrome_appcache_service.h" | 
| +#include "content/browser/loader/url_loader_request_handler.h" | 
| #include "content/browser/url_loader_factory_getter.h" | 
| -#include "content/common/network_service.mojom.h" | 
| #include "content/common/resource_request.h" | 
| #include "content/common/url_loader.mojom.h" | 
| #include "content/common/url_loader_factory.mojom.h" | 
| @@ -20,49 +24,122 @@ | 
| #include "mojo/public/cpp/bindings/binding.h" | 
| #include "mojo/public/cpp/bindings/binding_set.h" | 
| #include "mojo/public/cpp/bindings/interface_ptr.h" | 
| +#include "mojo/public/cpp/system/data_pipe.h" | 
| +#include "net/base/io_buffer.h" | 
| +#include "net/http/http_response_headers.h" | 
| namespace content { | 
| -namespace { | 
| - | 
| -// Handles AppCache URL loads for the network service. | 
| -class AppCacheURLLoader : public AppCacheStorage::Delegate, | 
| - public mojom::URLLoader { | 
| +// This class implements the URLLoader mojom which provides functionality to | 
| +// service URL loads from the AppCache. It is also invoked for navigation | 
| +// requests to check if they can be serviced from the AppCache. If yes then | 
| +// it creates an instance of the AppCacheURLLoaderFactory class and passes it | 
| +// to the LoaderFactoryCallback callback. If not it invokes the | 
| +// LoaderFactoryCallback with a null factory pointer which passes the request | 
| +// to the next handler. | 
| +class AppCacheURLLoader : public mojom::URLLoader, | 
| + public AppCacheURLLoaderJob::Delegate { | 
| public: | 
| - AppCacheURLLoader(const ResourceRequest& request, | 
| - mojom::URLLoaderRequest url_loader_request, | 
| - int32_t routing_id, | 
| - int32_t request_id, | 
| - mojom::URLLoaderClientPtr client_info, | 
| - ChromeAppCacheService* appcache_service, | 
| - URLLoaderFactoryGetter* factory_getter) | 
| - : request_(request), | 
| - routing_id_(routing_id), | 
| - request_id_(request_id), | 
| - client_info_(std::move(client_info)), | 
| - appcache_service_(appcache_service), | 
| - factory_getter_(factory_getter), | 
| - binding_(this, std::move(url_loader_request)) { | 
| - binding_.set_connection_error_handler(base::Bind( | 
| - &AppCacheURLLoader::OnConnectionError, base::Unretained(this))); | 
| + // Creates an instance of the AppCacheURLLoader class which checks if the | 
| + // navigation |request| can be served via AppCache. If yes it creates an | 
| + // instance of the AppCacheURLLoaderFactory class and passes it to the | 
| + // |callback|. If not it invokes the callback with a null factory which | 
| + // indicates that the next handler should be invoked. | 
| + static AppCacheURLLoader* CreateForNavigationRequest( | 
| + const ResourceRequest& request, | 
| + ChromeAppCacheService* appcache_service, | 
| + LoaderFactoryCallback callback, | 
| + URLLoaderFactoryGetter* factory_getter) { | 
| + AppCacheURLLoader* loader = new AppCacheURLLoader( | 
| + request, appcache_service, std::move(callback), factory_getter); | 
| + return loader; | 
| + } | 
| + | 
| + // Creates an instance of the AppCacheURLLoader class which is used to handle | 
| + // URL requests from the client. We expect this function to be called for | 
| + // handling subresource requests. | 
| + static AppCacheURLLoader* CreateForURLLoads( | 
| + const ResourceRequest& request, | 
| + mojom::URLLoaderRequest url_loader_request, | 
| + int32_t routing_id, | 
| + int32_t request_id, | 
| + mojom::URLLoaderClientPtr client_info, | 
| + ChromeAppCacheService* appcache_service, | 
| + URLLoaderFactoryGetter* factory_getter) { | 
| + AppCacheURLLoader* loader = new AppCacheURLLoader( | 
| + request, std::move(url_loader_request), routing_id, request_id, | 
| + std::move(client_info), appcache_service, factory_getter); | 
| + return loader; | 
| } | 
| ~AppCacheURLLoader() override {} | 
| - void Start() { | 
| + // Starts the process of checking if the request can be served from the | 
| + // AppCache. | 
| + void Start(AppCacheHost* host) { | 
| + DCHECK(host); | 
| // If the origin does not exist in the AppCache usage map, then we can | 
| - // safely call the network service here. | 
| - if (appcache_service_->storage()->usage_map()->find( | 
| + // safely call the network service or pass it to the next handler. | 
| + if (appcache_service_->storage()->IsInitialized() && | 
| + appcache_service_->storage()->usage_map()->find( | 
| 
michaeln
2017/06/02 01:18:00
this test is only valid for main resource loads, c
 
ananta
2017/06/02 03:19:57
Done.
 
ananta
2017/06/03 01:55:55
No longer needed with the handler and the job impl
 | 
| request_.url.GetOrigin()) == | 
| - appcache_service_->storage()->usage_map()->end()) { | 
| - factory_getter_->GetNetworkFactory()->get()->CreateLoaderAndStart( | 
| - mojo::MakeRequest(&network_loader_request_), routing_id_, request_id_, | 
| - mojom::kURLLoadOptionSendSSLInfo, request_, std::move(client_info_)); | 
| + appcache_service_->storage()->usage_map()->end()) { | 
| + SendNetworkResponse(); | 
| return; | 
| } | 
| - appcache_service_->storage()->FindResponseForMainRequest(request_.url, | 
| - GURL(), this); | 
| + if (IsResourceTypeFrame(request_.resource_type)) { | 
| + handler_ = host->CreateRequestHandler( | 
| + AppCacheURLLoaderRequest::Create(request_), request_.resource_type, | 
| + request_.should_reset_appcache); | 
| + | 
| + AppCacheJob* job = handler_->MaybeLoadResource(nullptr); | 
| + if (!job) { | 
| + SendNetworkResponse(); | 
| + return; | 
| + } | 
| + | 
| + job_.reset(job->AsURLLoaderJob()); | 
| + job_->set_delegate(this); | 
| + } else { | 
| + // We should not be hitting this yet. We have to plumb the AppCache | 
| + // response through to the renderer before we receive requests for sub | 
| + // resources. | 
| + DCHECK(false); | 
| + } | 
| + } | 
| + | 
| + // Binds the client end point with this instance. | 
| + void BindEndpoints(const ResourceRequest& request, | 
| + mojom::URLLoaderRequest url_loader_request, | 
| + int32_t routing_id, | 
| + int32_t request_id, | 
| + mojom::URLLoaderClientPtrInfo client_info) { | 
| + request_ = request; | 
| + | 
| + binding_.reset(new mojo::Binding<mojom::URLLoader>( | 
| + this, std::move(url_loader_request))); | 
| + binding_->set_connection_error_handler(base::Bind( | 
| + &AppCacheURLLoader::OnConnectionError, base::Unretained(this))); | 
| + | 
| + routing_id_ = routing_id; | 
| + request_id_ = request_id; | 
| + | 
| + client_info_.Bind(std::move(client_info)); | 
| + | 
| + // We pass the cached AppCache response and the data to the client for | 
| + // navigation requests. | 
| + if (navigation_request_) { | 
| + DCHECK(cached_response_info_.get()); | 
| + HandleAppCacheResponseInternal(cached_response_info_.get()); | 
| + cached_response_info_ = nullptr; | 
| + | 
| + if (cached_buffer_.get()) { | 
| + HandleAppCacheDataInternal(cached_buffer_.get(), cached_buffer_size_); | 
| + cached_buffer_ = nullptr; | 
| + cached_buffer_size_ = 0; | 
| + } | 
| + } | 
| } | 
| // mojom::URLLoader implementation: | 
| @@ -73,39 +150,149 @@ class AppCacheURLLoader : public AppCacheStorage::Delegate, | 
| DCHECK(false); | 
| } | 
| - private: | 
| - // AppCacheStorage::Delegate methods. | 
| - void OnMainResponseFound(const GURL& url, | 
| - const AppCacheEntry& entry, | 
| - const GURL& fallback_url, | 
| - const AppCacheEntry& fallback_entry, | 
| - int64_t cache_id, | 
| - int64_t group_id, | 
| - const GURL& manifest_url) override { | 
| - AppCachePolicy* policy = appcache_service_->appcache_policy(); | 
| - bool was_blocked_by_policy = | 
| - !manifest_url.is_empty() && policy && | 
| - !policy->CanLoadAppCache(manifest_url, | 
| - request_.first_party_for_cookies); | 
| - | 
| - if (was_blocked_by_policy || !entry.has_response_id() || | 
| - cache_id == kAppCacheNoCacheId) { | 
| - factory_getter_->GetNetworkFactory()->get()->CreateLoaderAndStart( | 
| - mojo::MakeRequest(&network_loader_request_), routing_id_, request_id_, | 
| - mojom::kURLLoadOptionSendSSLInfo, request_, std::move(client_info_)); | 
| + // AppCacheURLLoaderJob::Delegate overrides. | 
| + void SendNetworkResponse() override { | 
| + // For a navigation request we invoke the LoaderFactoryCallback with null to | 
| + // ensure that the next handler gets a stab at the request. | 
| + if (navigation_request_) { | 
| + std::move(callback_).Run(nullptr); | 
| + base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, this); | 
| } else { | 
| - DLOG(WARNING) << "AppCache found for url " << url | 
| - << " Returning AppCache factory\n"; | 
| // TODO(ananta) | 
| - // Provide the plumbing to initiate AppCache requests here. | 
| + // We probably need to chain to the next factory instead of always | 
| + // passing the request to the network factory. This code path will | 
| + // only execute for subresources. | 
| factory_getter_->GetNetworkFactory()->get()->CreateLoaderAndStart( | 
| mojo::MakeRequest(&network_loader_request_), routing_id_, request_id_, | 
| mojom::kURLLoadOptionSendSSLInfo, request_, std::move(client_info_)); | 
| } | 
| } | 
| + void SendErrorResponse() override { | 
| + DLOG(WARNING) << "Sending error response for URL: " << request_.url; | 
| 
michaeln
2017/06/02 01:18:00
TODO for this?
 
ananta
2017/06/02 03:19:57
Done.
 | 
| + } | 
| + | 
| + void HandleAppCacheResponseStart(AppCacheResponseInfo* response_info) | 
| + override { | 
| + DCHECK(response_info); | 
| + DCHECK(response_info->http_response_info()); | 
| + | 
| + // For a navigation request, we create an instance of the | 
| + // AppCacheURLLoaderFactory class which implements the URLLoaderFactory | 
| + // interface and pass it to the LoaderFactoryCallback. | 
| + if (navigation_request_) { | 
| + // Cache the response here to be passed to the client when it connects to | 
| + // us. | 
| + cached_response_info_ = response_info; | 
| + mojom::URLLoaderFactoryPtr appcache_factory; | 
| + AppCacheURLLoaderFactory::CreateURLLoaderFactory( | 
| + mojo::MakeRequest(&appcache_factory), appcache_service_.get(), | 
| + factory_getter_.get(), this, 0); | 
| + std::move(callback_).Run(appcache_factory.get()); | 
| + return; | 
| + } | 
| + | 
| + HandleAppCacheResponseInternal(response_info); | 
| + } | 
| + | 
| + void HandleAppCacheData(net::IOBuffer* buffer, int buffer_size) override { | 
| + DLOG(WARNING) << "Received AppCache data for URL: " << request_.url; | 
| + | 
| + // Cache the buffer and the size. We will use it later when the client | 
| + // connects to us via URLLoaderFactory::CreateLoaderAndStart(). | 
| + | 
| + // If the cached AppCacheResponseInfo member is null, it means that the | 
| + // client has already connected to us. It is safe to forward the buffer | 
| + // directly to the client. | 
| + if (navigation_request_ && cached_response_info_.get()) { | 
| + cached_buffer_ = buffer; | 
| + cached_buffer_size_ = buffer_size; | 
| + return; | 
| + } | 
| + | 
| + HandleAppCacheDataInternal(buffer, buffer_size); | 
| + } | 
| + | 
| + private: | 
| + // This ctor is used for checking if navigation requests can be served from | 
| + // the AppCache. | 
| + AppCacheURLLoader(const ResourceRequest& request, | 
| + ChromeAppCacheService* appcache_service, | 
| + LoaderFactoryCallback callback, | 
| + URLLoaderFactoryGetter* factory_getter) | 
| + : appcache_service_(appcache_service), | 
| + factory_getter_(factory_getter), | 
| + request_(request), | 
| + routing_id_(-1), | 
| + request_id_(-1), | 
| + callback_(std::move(callback)), | 
| + cached_buffer_size_(0), | 
| + navigation_request_(true) {} | 
| + | 
| + // This ctor is used for handling URL load requests. | 
| + AppCacheURLLoader(const ResourceRequest& request, | 
| + mojom::URLLoaderRequest url_loader_request, | 
| + int32_t routing_id, | 
| + int32_t request_id, | 
| + mojom::URLLoaderClientPtr client_info, | 
| + ChromeAppCacheService* appcache_service, | 
| + URLLoaderFactoryGetter* factory_getter) | 
| + : appcache_service_(appcache_service), | 
| + factory_getter_(factory_getter), | 
| + cached_buffer_size_(0), | 
| + navigation_request_(false) { | 
| + BindEndpoints(request, std::move(url_loader_request), routing_id, | 
| + request_id, client_info.PassInterface()); | 
| + } | 
| + | 
| void OnConnectionError() { delete this; } | 
| + void HandleAppCacheResponseInternal(AppCacheResponseInfo* response_info) { | 
| + DLOG(WARNING) << "Received AppCache response for URL: " << request_.url; | 
| + | 
| + const net::HttpResponseInfo* http_info = | 
| + response_info->http_response_info(); | 
| + | 
| + ResourceResponseHead response_head; | 
| + response_head.headers = new net::HttpResponseHeaders(""); | 
| + | 
| + std::string name; | 
| + std::string value; | 
| + | 
| + for (size_t it = 0; | 
| + http_info->headers->EnumerateHeaderLines(&it, &name, &value);) { | 
| + response_head.headers->AddHeader(name + ": " + value); | 
| + } | 
| + | 
| + // TODO(ananta) | 
| + // Copy more fields. | 
| + http_info->headers->GetMimeType(&response_head.mime_type); | 
| + http_info->headers->GetCharset(&response_head.charset); | 
| + | 
| + response_head.request_time = http_info->request_time; | 
| + response_head.response_time = http_info->response_time; | 
| + response_head.content_length = response_info->response_data_size(); | 
| + | 
| + client_info_->OnReceiveResponse(response_head, http_info->ssl_info, | 
| + mojom::DownloadedTempFilePtr()); | 
| + } | 
| + | 
| + void HandleAppCacheDataInternal(net::IOBuffer* buffer, int buffer_size) { | 
| + uint32_t bytes_written = static_cast<uint32_t>(buffer_size); | 
| + mojo::WriteDataRaw(data_pipe_.producer_handle.get(), buffer->data(), | 
| + &bytes_written, MOJO_WRITE_DATA_FLAG_NONE); | 
| + client_info_->OnStartLoadingResponseBody( | 
| + std::move(data_pipe_.consumer_handle)); | 
| + } | 
| + | 
| + // Used to query AppCacheStorage to see if a request can be served out of the | 
| + /// AppCache. | 
| + scoped_refptr<ChromeAppCacheService> appcache_service_; | 
| + | 
| + // Used to retrieve the network service factory to pass requests to the | 
| + // network service. | 
| + scoped_refptr<URLLoaderFactoryGetter> factory_getter_; | 
| + | 
| // The current request. | 
| ResourceRequest request_; | 
| @@ -123,27 +310,91 @@ class AppCacheURLLoader : public AppCacheStorage::Delegate, | 
| // about the URL load | 
| mojom::URLLoaderClientPtr client_info_; | 
| - // Used to query AppCacheStorage to see if a request can be served out of the | 
| - /// AppCache. | 
| - scoped_refptr<ChromeAppCacheService> appcache_service_; | 
| + // Binds the URLLoaderClient with us. | 
| + std::unique_ptr<mojo::Binding<mojom::URLLoader>> binding_; | 
| - // Used to retrieve the network service factory to pass requests to the | 
| - // network service. | 
| - scoped_refptr<URLLoaderFactoryGetter> factory_getter_; | 
| + // The handler for the AppCache request. | 
| + std::unique_ptr<AppCacheRequestHandler> handler_; | 
| - // Binds the URLLoaderClient with us. | 
| - mojo::Binding<mojom::URLLoader> binding_; | 
| + // The job which gets invoked by the handler to deliver the responses to the | 
| + // client. | 
| + std::unique_ptr<AppCacheURLLoaderJob> job_; | 
| + | 
| + // The data pipe used to transfer AppCache data to the client. | 
| + mojo::DataPipe data_pipe_; | 
| + | 
| + // Callback to be invoked with the AppCache factory or null to fall through | 
| + // to the next handler in the chain. | 
| + LoaderFactoryCallback callback_; | 
| + | 
| + // Cached AppCache response to be used later when we are initialized with | 
| + // the connection end point. | 
| + scoped_refptr<AppCacheResponseInfo> cached_response_info_; | 
| + | 
| + // Cached IOBuffer to be used later when we are initialized with the | 
| + // connection end point. | 
| + scoped_refptr<net::IOBuffer> cached_buffer_; | 
| + | 
| + // Cached buffer size to be used later when we are initialized with the | 
| + // connection end point. | 
| + int cached_buffer_size_; | 
| + | 
| + // Set to true for navigation requests. | 
| + bool navigation_request_; | 
| DISALLOW_COPY_AND_ASSIGN(AppCacheURLLoader); | 
| }; | 
| -} // namespace | 
| +// This class is instantiated for navigation requests. It initiates checks on | 
| +// whether the request can be serviced via the AppCache. | 
| +// It uses the AppCacheURLLoader class defined above for this. If the request | 
| +// cannot be serviced via AppCache, the AppCacheURLLoader class calls | 
| +// the LoaderFactoryCallback with a null factory which ensures that the request | 
| +// goes to the next handler in the chain. | 
| +// If the request can be serviced with AppCache the AppCacheURLLoader class | 
| +// creates an instance of the AppCacheURLLoaderFactory class and passes it to | 
| +// the LoaderFactoryCallback function. | 
| +class AppCacheNavigationRequestHandler : public URLLoaderRequestHandler { | 
| + public: | 
| + AppCacheNavigationRequestHandler( | 
| + AppCacheNavigationHandleCore* appcache_handle_core, | 
| + URLLoaderFactoryGetter* url_loader_factory_getter) | 
| + : appcache_core_(appcache_handle_core), | 
| + factory_getter_(url_loader_factory_getter) {} | 
| + | 
| + void MaybeCreateLoaderFactory(const ResourceRequest& resource_request, | 
| + ResourceContext* resource_context, | 
| + LoaderFactoryCallback callback) override { | 
| + // The AppCacheURLLoader instance will be deleted when the URL load request | 
| + // completes. It can complete in the following ways: | 
| + // 1. The request is serviced via AppCache. In this case it is deleted when | 
| + // the connection is dropped by the client. | 
| + // 2. The request is serviced by the next handler. | 
| + AppCacheURLLoader* loader = AppCacheURLLoader::CreateForNavigationRequest( | 
| 
michaeln
2017/06/02 01:18:00
The way this reads, we're creating a resulting loa
 
ananta
2017/06/03 01:55:55
This class has been removed now. The job implement
 | 
| + resource_request, appcache_core_->GetAppCacheService(), | 
| + std::move(callback), factory_getter_.get()); | 
| + loader->Start(appcache_core_->host()); | 
| + } | 
| + | 
| + private: | 
| + AppCacheNavigationHandleCore* appcache_core_; | 
| + // Used to retrieve the network service factory to pass requests to the | 
| + // network service. | 
| + scoped_refptr<URLLoaderFactoryGetter> factory_getter_; | 
| + | 
| + DISALLOW_COPY_AND_ASSIGN(AppCacheNavigationRequestHandler); | 
| +}; | 
| // Implements the URLLoaderFactory mojom for AppCache requests. | 
| AppCacheURLLoaderFactory::AppCacheURLLoaderFactory( | 
| ChromeAppCacheService* appcache_service, | 
| - URLLoaderFactoryGetter* factory_getter) | 
| - : appcache_service_(appcache_service), factory_getter_(factory_getter) {} | 
| + URLLoaderFactoryGetter* factory_getter, | 
| + AppCacheURLLoader* navigation_url_loader, | 
| + int process_id) | 
| + : appcache_service_(appcache_service), | 
| + factory_getter_(factory_getter), | 
| + navigation_url_loader_(navigation_url_loader), | 
| + process_id_(process_id) {} | 
| AppCacheURLLoaderFactory::~AppCacheURLLoaderFactory() {} | 
| @@ -151,14 +402,28 @@ AppCacheURLLoaderFactory::~AppCacheURLLoaderFactory() {} | 
| void AppCacheURLLoaderFactory::CreateURLLoaderFactory( | 
| mojom::URLLoaderFactoryRequest request, | 
| ChromeAppCacheService* appcache_service, | 
| - URLLoaderFactoryGetter* factory_getter) { | 
| + URLLoaderFactoryGetter* factory_getter, | 
| + AppCacheURLLoader* navigation_url_loader, | 
| + int process_id) { | 
| std::unique_ptr<AppCacheURLLoaderFactory> factory_instance( | 
| - new AppCacheURLLoaderFactory(appcache_service, factory_getter)); | 
| + new AppCacheURLLoaderFactory(appcache_service, factory_getter, | 
| + navigation_url_loader, process_id)); | 
| AppCacheURLLoaderFactory* raw_factory = factory_instance.get(); | 
| raw_factory->loader_factory_bindings_.AddBinding(std::move(factory_instance), | 
| std::move(request)); | 
| } | 
| +// static | 
| +std::unique_ptr<URLLoaderRequestHandler> | 
| +AppCacheURLLoaderFactory::CreateRequestHandler( | 
| + AppCacheNavigationHandleCore* appcache_handle_core, | 
| + URLLoaderFactoryGetter* url_loader_factory_getter) { | 
| + std::unique_ptr<URLLoaderRequestHandler> handler( | 
| + new AppCacheNavigationRequestHandler(appcache_handle_core, | 
| + url_loader_factory_getter)); | 
| + return handler; | 
| +} | 
| + | 
| void AppCacheURLLoaderFactory::CreateLoaderAndStart( | 
| mojom::URLLoaderRequest url_loader_request, | 
| int32_t routing_id, | 
| @@ -168,11 +433,25 @@ void AppCacheURLLoaderFactory::CreateLoaderAndStart( | 
| mojom::URLLoaderClientPtr client) { | 
| DCHECK_CURRENTLY_ON(BrowserThread::IO); | 
| + AppCacheHost* host = nullptr; | 
| + // If we have an ongoing navigation, bind the endpoints here. | 
| + if (navigation_url_loader_) { | 
| + navigation_url_loader_->BindEndpoints( | 
| + request, std::move(url_loader_request), routing_id, request_id, | 
| + client.PassInterface()); | 
| + return; | 
| + } else { | 
| + AppCacheBackendImpl* backend = appcache_service_->GetBackend(process_id_); | 
| + DCHECK(backend); | 
| + host = backend->GetHost(request.appcache_host_id); | 
| + DCHECK(host); | 
| + } | 
| + | 
| // This will get deleted when the connection is dropped by the client. | 
| - AppCacheURLLoader* loader = new AppCacheURLLoader( | 
| + AppCacheURLLoader* loader = AppCacheURLLoader::CreateForURLLoads( | 
| request, std::move(url_loader_request), routing_id, request_id, | 
| std::move(client), appcache_service_.get(), factory_getter_.get()); | 
| - loader->Start(); | 
| + loader->Start(host); | 
| } | 
| void AppCacheURLLoaderFactory::SyncLoad(int32_t routing_id, |