Initial implementation of SignedExchangeHandler and WebPackage response handling.

This CL implements the following classes:
 - SignedExchangeHandler
 - WebPackageLoader
 - WebPackageRequestHandler

But Currenly SignedExchangeHandler doesn't implement any CBOR parsing logic nor
verifying logic. It just behaves as if the passed body is a signed HTTP exchange
which contains a request to "https://example.com/test.html" and a response with
a payload which is equal to the original body.

The added LayoutTest "origin-signed-response.html" must pass only when
SignedHTTPExchange feature is enabled.

Bug: 803774

Change-Id: I53d397d7cdfe79d48d6891db65ab1a1e12100b92
Reviewed-on: https://chromium-review.googlesource.com/869872
Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531921}

content/browser/BUILD.gn

@@ -1012,6 +1012,8 @@ jumbo_source_set("browser") {
     "loader/resource_requester_info.h",
     "loader/resource_scheduler_filter.cc",
     "loader/resource_scheduler_filter.h",
+    "loader/signed_exchange_handler.cc",
+    "loader/signed_exchange_handler.h",
     "loader/stream_resource_handler.cc",
     "loader/stream_resource_handler.h",
     "loader/stream_writer.cc",
@@ -1028,6 +1030,10 @@ jumbo_source_set("browser") {
     "loader/url_loader_request_handler.h",
     "loader/wake_lock_resource_throttle.cc",
     "loader/wake_lock_resource_throttle.h",
+    "loader/web_package_loader.cc",
+    "loader/web_package_loader.h",
+    "loader/web_package_request_handler.cc",
+    "loader/web_package_request_handler.h",
     "loader_delegate_impl.cc",
     "loader_delegate_impl.h",
     "locks/lock_manager.cc",

content/browser/appcache/appcache_request_handler.cc

@@ -600,7 +600,8 @@ void AppCacheRequestHandler::MaybeCreateLoader(
 bool AppCacheRequestHandler::MaybeCreateLoaderForResponse(
     const network::ResourceResponseHead& response,
     network::mojom::URLLoaderPtr* loader,
-    network::mojom::URLLoaderClientRequest* client_request) {
+    network::mojom::URLLoaderClientRequest* client_request,
+    ThrottlingURLLoader* url_loader) {
   // The sync interface of this method is inherited from the
   // URLLoaderRequestHandler class. The LoaderCallback created here is invoked
   // synchronously in fallback cases, and only when there really is a loader

content/browser/appcache/appcache_request_handler.h

@@ -93,7 +93,8 @@ class CONTENT_EXPORT AppCacheRequestHandler
   bool MaybeCreateLoaderForResponse(
       const network::ResourceResponseHead& response,
       network::mojom::URLLoaderPtr* loader,
-      network::mojom::URLLoaderClientRequest* client_request) override;
+      network::mojom::URLLoaderClientRequest* client_request,
+      ThrottlingURLLoader* url_loader) override;
   base::Optional<SubresourceLoaderParams> MaybeCreateSubresourceLoaderParams()
       override;
 

content/browser/loader/mime_sniffing_resource_handler.cc

@@ -8,6 +8,7 @@
 #include <vector>
 
 #include "base/bind.h"
+#include "base/feature_list.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
@@ -20,6 +21,7 @@
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/browser/loader/stream_resource_handler.h"
+#include "content/browser/loader/web_package_request_handler.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_save_info.h"
@@ -27,6 +29,7 @@
 #include "content/public/browser/plugin_service.h"
 #include "content/public/browser/resource_context.h"
 #include "content/public/browser/resource_dispatcher_host_delegate.h"
+#include "content/public/common/content_features.h"
 #include "content/public/common/webplugininfo.h"
 #include "net/base/io_buffer.h"
 #include "net/base/mime_sniffer.h"
@@ -414,6 +417,10 @@ bool MimeSniffingResourceHandler::MaybeStartInterception() {
   if (!must_download) {
     if (blink::IsSupportedMimeType(mime_type))
       return true;
+    if (base::FeatureList::IsEnabled(features::kSignedHTTPExchange) &&
+        WebPackageRequestHandler::IsSupportedMimeType(mime_type)) {
+      return true;
+    }
 
     bool handled_by_plugin;
     if (!CheckForPluginHandler(&handled_by_plugin))

content/browser/loader/navigation_url_loader_network_service.cc

@@ -22,6 +22,7 @@
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/browser/loader/url_loader_request_handler.h"
+#include "content/browser/loader/web_package_request_handler.h"
 #include "content/browser/resource_context_impl.h"
 #include "content/browser/service_worker/service_worker_navigation_handle.h"
 #include "content/browser/service_worker/service_worker_navigation_handle_core.h"
@@ -64,6 +65,11 @@ namespace content {
 
 namespace {
 
+bool IsRequestHandlerEnabled() {
+  return base::FeatureList::IsEnabled(features::kNetworkService) ||
+         base::FeatureList::IsEnabled(features::kSignedHTTPExchange);
+}
+
 // Request ID for browser initiated requests. We start at -2 on the same lines
 // as ResourceDispatcherHostImpl.
 int g_next_request_id = -2;
@@ -177,6 +183,61 @@ bool IsDownload(const network::ResourceResponse& response,
           response.head.headers->response_code() / 100 == 2);
 }
 
+std::unique_ptr<network::ResourceRequest> CreateResourceRequest(
+    NavigationRequestInfo* request_info,
+    int frame_tree_node_id,
+    bool allow_download) {
+  // TODO(scottmg): Port over stuff from RDHI::BeginNavigationRequest() here.
+  auto new_request = std::make_unique<network::ResourceRequest>();
+
+  new_request->method = request_info->common_params.method;
+  new_request->url = request_info->common_params.url;
+  new_request->site_for_cookies = request_info->site_for_cookies;
+  new_request->priority = net::HIGHEST;
+  new_request->render_frame_id = frame_tree_node_id;
+
+  // The code below to set fields like request_initiator, referrer, etc has
+  // been copied from ResourceDispatcherHostImpl. We did not refactor the
+  // common code into a function, because RDHI uses accessor functions on the
+  // URLRequest class to set these fields. whereas we use ResourceRequest here.
+  new_request->request_initiator = request_info->begin_params->initiator_origin;
+  new_request->referrer = request_info->common_params.referrer.url;
+  new_request->referrer_policy = Referrer::ReferrerPolicyForUrlRequest(
+      request_info->common_params.referrer.policy);
+  new_request->headers.AddHeadersFromString(
+      request_info->begin_params->headers);
+  new_request->headers.SetHeader(network::kAcceptHeader,
+                                 network::kFrameAcceptHeader);
+
+  new_request->resource_type = request_info->is_main_frame
+                                   ? RESOURCE_TYPE_MAIN_FRAME
+                                   : RESOURCE_TYPE_SUB_FRAME;
+  if (request_info->is_main_frame)
+    new_request->update_first_party_url_on_redirect = true;
+
+  int load_flags = request_info->begin_params->load_flags;
+  load_flags |= net::LOAD_VERIFY_EV_CERT;
+  if (request_info->is_main_frame)
+    load_flags |= net::LOAD_MAIN_FRAME_DEPRECATED;
+
+  // Sync loads should have maximum priority and should be the only
+  // requests that have the ignore limits flag set.
+  DCHECK(!(load_flags & net::LOAD_IGNORE_LIMITS));
+
+  new_request->load_flags = load_flags;
+
+  new_request->request_body = request_info->common_params.post_data.get();
+  new_request->report_raw_headers = request_info->report_raw_headers;
+  new_request->allow_download = allow_download;
+  new_request->enable_load_timing = true;
+
+  new_request->fetch_request_mode = network::mojom::FetchRequestMode::kNavigate;
+  new_request->fetch_credentials_mode =
+      network::mojom::FetchCredentialsMode::kInclude;
+  new_request->fetch_redirect_mode = network::mojom::FetchRedirectMode::kManual;
+  return new_request;
+}
+
 }  // namespace
 
 // Kept around during the lifetime of the navigation request, and is
@@ -242,6 +303,11 @@ class NavigationURLLoaderNetworkService::URLLoaderRequestController
     DCHECK(!base::FeatureList::IsEnabled(features::kNetworkService));
     DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
+    default_loader_used_ = true;
+    if (base::FeatureList::IsEnabled(features::kSignedHTTPExchange)) {
+      handlers_.push_back(base::MakeUnique<WebPackageRequestHandler>());
+    }
+
     // The ResourceDispatcherHostImpl can be null in unit tests.
     if (ResourceDispatcherHostImpl::Get()) {
       ResourceDispatcherHostImpl::Get()->BeginNavigationRequest(
@@ -363,12 +429,16 @@ class NavigationURLLoaderNetworkService::URLLoaderRequestController
         handlers_.push_back(std::move(appcache_handler));
     }
 
+    if (base::FeatureList::IsEnabled(features::kSignedHTTPExchange)) {
+      handlers_.push_back(base::MakeUnique<WebPackageRequestHandler>());
+    }
+
     Restart();
   }
 
   // This could be called multiple times to follow a chain of redirects.
   void Restart() {
-    DCHECK(base::FeatureList::IsEnabled(features::kNetworkService));
+    DCHECK(IsRequestHandlerEnabled());
     // Clear |url_loader_| if it's not the default one (network). This allows
     // the restarted request to use a new loader, instead of, e.g., reusing the
     // AppCache or service worker loader. For an optimization, we keep and reuse
@@ -387,15 +457,17 @@ class NavigationURLLoaderNetworkService::URLLoaderRequestController
   // if the |handler| wants to handle the request.
   void MaybeStartLoader(URLLoaderRequestHandler* handler,
                         StartLoaderCallback start_loader_callback) {
-    DCHECK(base::FeatureList::IsEnabled(features::kNetworkService));
+    DCHECK(IsRequestHandlerEnabled());
     if (start_loader_callback) {
       // |handler| wants to handle the request.
       DCHECK(handler);
       default_loader_used_ = false;
       url_loader_ = ThrottlingURLLoader::CreateLoaderAndStart(
           std::move(start_loader_callback),
-          GetContentClient()->browser()->CreateURLLoaderThrottles(
-              web_contents_getter_, navigation_ui_data_.get()),
+          base::FeatureList::IsEnabled(features::kNetworkService)
+              ? GetContentClient()->browser()->CreateURLLoaderThrottles(
+                    web_contents_getter_, navigation_ui_data_.get())
+              : std::vector<std::unique_ptr<content::URLLoaderThrottle>>(),
           frame_tree_node_id_, resource_request_.get(), this,
           kNavigationUrlLoaderTrafficAnnotation,
           base::ThreadTaskRunnerHandle::Get());
@@ -479,13 +551,8 @@ class NavigationURLLoaderNetworkService::URLLoaderRequestController
   void FollowRedirect() {
     DCHECK_CURRENTLY_ON(BrowserThread::IO);
     DCHECK(!redirect_info_.new_url.is_empty());
-    DCHECK(!response_url_loader_);
-    DCHECK(url_loader_);
 
-    // TODO(arthursonzogni): We might need to go through the rest of the
-    // function once there are several types of URLLoader handling the
-    // navigation, even in non network-service mode.
-    if (!base::FeatureList::IsEnabled(features::kNetworkService)) {
+    if (!IsRequestHandlerEnabled()) {
       url_loader_->FollowRedirect();
       return;
     }
@@ -554,7 +621,7 @@ class NavigationURLLoaderNetworkService::URLLoaderRequestController
     bool is_download;
     bool is_stream;
     std::unique_ptr<NavigationData> cloned_navigation_data;
-    if (base::FeatureList::IsEnabled(features::kNetworkService)) {
+    if (IsRequestHandlerEnabled()) {
       is_download = IsDownload(*response.get(), url_, url_chain_,
                                initiator_origin_, suggested_filename_);
       is_stream = false;
@@ -663,7 +730,7 @@ class NavigationURLLoaderNetworkService::URLLoaderRequestController
   // different response. For e.g. AppCache may have fallback content.
   bool MaybeCreateLoaderForResponse(
       const network::ResourceResponseHead& response) {
-    if (!base::FeatureList::IsEnabled(features::kNetworkService))
+    if (!IsRequestHandlerEnabled())
       return false;
 
     if (!default_loader_used_)
@@ -672,7 +739,8 @@ class NavigationURLLoaderNetworkService::URLLoaderRequestController
     for (auto& handler : handlers_) {
       network::mojom::URLLoaderClientRequest response_client_request;
       if (handler->MaybeCreateLoaderForResponse(response, &response_url_loader_,
-                                                &response_client_request)) {
+                                                &response_client_request,
+                                                url_loader_.get())) {
         response_loader_binding_.Bind(std::move(response_client_request));
         default_loader_used_ = false;
         url_loader_.reset();
@@ -781,12 +849,18 @@ NavigationURLLoaderNetworkService::NavigationURLLoaderNetworkService(
   AppCacheNavigationHandleCore* appcache_handle_core =
       appcache_handle ? appcache_handle->core() : nullptr;
 
+  std::unique_ptr<network::ResourceRequest> new_request;
+  if (IsRequestHandlerEnabled()) {
+    new_request = CreateResourceRequest(request_info.get(), frame_tree_node_id,
+                                        allow_download_);
+  }
+
   if (!base::FeatureList::IsEnabled(features::kNetworkService)) {
     DCHECK(!request_controller_);
     request_controller_ = std::make_unique<URLLoaderRequestController>(
         /* initial_handlers = */
         std::vector<std::unique_ptr<URLLoaderRequestHandler>>(),
-        /* resource_request = */ nullptr, resource_context,
+        std::move(new_request), resource_context,
         /* default_url_factory_getter = */ nullptr,
         request_info->common_params.url,
         request_info->begin_params->initiator_origin,
@@ -807,55 +881,6 @@ NavigationURLLoaderNetworkService::NavigationURLLoaderNetworkService(
     return;
   }
 
-  // TODO(scottmg): Port over stuff from RDHI::BeginNavigationRequest() here.
-  auto new_request = std::make_unique<network::ResourceRequest>();
-
-  new_request->method = request_info->common_params.method;
-  new_request->url = request_info->common_params.url;
-  new_request->site_for_cookies = request_info->site_for_cookies;
-  new_request->priority = net::HIGHEST;
-  new_request->render_frame_id = frame_tree_node_id;
-
-  // The code below to set fields like request_initiator, referrer, etc has
-  // been copied from ResourceDispatcherHostImpl. We did not refactor the
-  // common code into a function, because RDHI uses accessor functions on the
-  // URLRequest class to set these fields. whereas we use ResourceRequest here.
-  new_request->request_initiator = request_info->begin_params->initiator_origin;
-  new_request->referrer = request_info->common_params.referrer.url;
-  new_request->referrer_policy = Referrer::ReferrerPolicyForUrlRequest(
-      request_info->common_params.referrer.policy);
-  new_request->headers.AddHeadersFromString(
-      request_info->begin_params->headers);
-  new_request->headers.SetHeader(network::kAcceptHeader,
-                                 network::kFrameAcceptHeader);
-
-  new_request->resource_type = request_info->is_main_frame
-                                   ? RESOURCE_TYPE_MAIN_FRAME
-                                   : RESOURCE_TYPE_SUB_FRAME;
-  if (request_info->is_main_frame)
-    new_request->update_first_party_url_on_redirect = true;
-
-  int load_flags = request_info->begin_params->load_flags;
-  load_flags |= net::LOAD_VERIFY_EV_CERT;
-  if (request_info->is_main_frame)
-    load_flags |= net::LOAD_MAIN_FRAME_DEPRECATED;
-
-  // Sync loads should have maximum priority and should be the only
-  // requests that have the ignore limits flag set.
-  DCHECK(!(load_flags & net::LOAD_IGNORE_LIMITS));
-
-  new_request->load_flags = load_flags;
-
-  new_request->request_body = request_info->common_params.post_data.get();
-  new_request->report_raw_headers = request_info->report_raw_headers;
-  new_request->allow_download = allow_download_;
-  new_request->enable_load_timing = true;
-
-  new_request->fetch_request_mode = network::mojom::FetchRequestMode::kNavigate;
-  new_request->fetch_credentials_mode =
-      network::mojom::FetchCredentialsMode::kInclude;
-  new_request->fetch_redirect_mode = network::mojom::FetchRedirectMode::kManual;
-
   // Check if a web UI scheme wants to handle this request.
   FrameTreeNode* frame_tree_node =
       FrameTreeNode::GloballyFindByID(frame_tree_node_id);

content/browser/loader/navigation_url_loader_network_service_unittest.cc

@@ -63,7 +63,8 @@ class TestURLLoaderRequestHandler : public URLLoaderRequestHandler {
   bool MaybeCreateLoaderForResponse(
       const network::ResourceResponseHead& response,
       network::mojom::URLLoaderPtr* loader,
-      network::mojom::URLLoaderClientRequest* client_request) override {
+      network::mojom::URLLoaderClientRequest* client_request,
+      ThrottlingURLLoader* url_loader) override {
     return false;
   }
 

content/browser/loader/signed_exchange_handler.cc

+// Copyright 2018 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 "content/browser/loader/signed_exchange_handler.h"
+
+#include "base/feature_list.h"
+#include "content/public/common/content_features.h"
+#include "mojo/public/cpp/system/string_data_pipe_producer.h"
+#include "net/http/http_response_headers.h"
+#include "services/network/public/cpp/resource_response.h"
+#include "services/network/public/cpp/url_loader_completion_status.h"
+
+namespace content {
+namespace {
+
+constexpr size_t kPipeSizeForSignedResponseBody = 65536;
+
+}  // namespace
+
+SignedExchangeHandler::SignedExchangeHandler(
+    mojo::ScopedDataPipeConsumerHandle body)
+    : body_(std::move(body)) {
+  DCHECK(base::FeatureList::IsEnabled(features::kSignedHTTPExchange));
+}
+
+SignedExchangeHandler::~SignedExchangeHandler() = default;
+
+void SignedExchangeHandler::GetHTTPExchange(
+    ExchangeFoundCallback found_callback,
+    ExchangeFinishedCallback finish_callback) {
+  DCHECK(!found_callback_);
+  DCHECK(!finish_callback_);
+  found_callback_ = std::move(found_callback);
+  finish_callback_ = std::move(finish_callback);
+
+  drainer_.reset(new mojo::common::DataPipeDrainer(this, std::move(body_)));
+}
+
+void SignedExchangeHandler::OnDataAvailable(const void* data,
+                                            size_t num_bytes) {
+  original_body_string_.append(static_cast<const char*>(data), num_bytes);
+}
+
+void SignedExchangeHandler::OnDataComplete() {
+  if (!found_callback_)
+    return;
+
+  // TODO(https://crbug.com/80374): Get the request url by parsing CBOR format.
+  GURL request_url = GURL("https://example.com/test.html");
+  // TODO(https://crbug.com/80374): Get the request method by parsing CBOR
+  // format.
+  std::string request_method = "GET";
+  // TODO(https://crbug.com/80374): Get the payload by parsing CBOR format.
+  std::string payload = original_body_string_;
+  original_body_string_.clear();
+
+  // TODO(https://crbug.com/80374): Get more headers by parsing CBOR.
+  scoped_refptr<net::HttpResponseHeaders> headers(
+      new net::HttpResponseHeaders("HTTP/1.1 200 OK"));
+  network::ResourceResponseHead resource_response;
+  resource_response.headers = headers;
+  resource_response.mime_type = "text/html";
+
+  // TODO(https://crbug.com/80374): Get the certificate by parsing CBOR and
+  // verify.
+  base::Optional<net::SSLInfo> ssl_info;
+
+  mojo::DataPipe pipe(kPipeSizeForSignedResponseBody);
+  // TODO(https://crbug.com/80374): Write the error handling code. This could
+  // fail.
+  DCHECK(pipe.consumer_handle.is_valid());
+  mojo::ScopedDataPipeConsumerHandle response_body =
+      std::move(pipe.consumer_handle);
+  std::move(found_callback_)
+      .Run(request_url, request_method, resource_response, std::move(ssl_info),
+           std::move(response_body));
+
+  data_producer_ = std::make_unique<mojo::StringDataPipeProducer>(
+      std::move(pipe.producer_handle));
+  data_producer_->Write(payload,
+                        base::BindOnce(&SignedExchangeHandler::OnDataWritten,
+                                       base::Unretained(this)));
+}
+
+void SignedExchangeHandler::OnDataWritten(MojoResult result) {
+  data_producer_.reset();
+  std::move(finish_callback_)
+      .Run(network::URLLoaderCompletionStatus(
+          result == MOJO_RESULT_OK ? net::OK : net::ERR_FAILED));
+}
+
+}  // namespace content

content/browser/loader/signed_exchange_handler.h

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_LOADER_SIGNED_EXCHANGE_HANDLER_H_
+#define CONTENT_BROWSER_LOADER_SIGNED_EXCHANGE_HANDLER_H_
+
+#include <string>
+
+#include "base/callback.h"
+#include "base/optional.h"
+#include "mojo/common/data_pipe_drainer.h"
+#include "mojo/public/cpp/system/data_pipe.h"
+#include "net/ssl/ssl_info.h"
+#include "url/gurl.h"
+
+namespace mojo {
+class StringDataPipeProducer;
+}  // namespace mojo
+
+namespace network {
+struct ResourceResponseHead;
+struct URLLoaderCompletionStatus;
+}  // namespace network
+
+namespace content {
+
+// IMPORTANT: Currenly SignedExchangeHandler doesn't implement any CBOR parsing
+// logic nor verifying logic. It just behaves as if the passed body is a signed
+// HTTP exchange which contains a request to "https://example.com/test.html" and
+// a response with a payload which is equal to the original body.
+// TODO(https://crbug.com/80374): Implement CBOR parsing logic and verifying
+// logic.
+class SignedExchangeHandler final
+    : public mojo::common::DataPipeDrainer::Client {
+ public:
+  using ExchangeFoundCallback =
+      base::OnceCallback<void(const GURL& request_url,
+                              const std::string& request_method,
+                              const network::ResourceResponseHead&,
+                              base::Optional<net::SSLInfo>,
+                              mojo::ScopedDataPipeConsumerHandle)>;
+  using ExchangeFinishedCallback =
+      base::OnceCallback<void(const network::URLLoaderCompletionStatus&)>;
+
+  // The passed |body| will be read to parse the signed HTTP exchange.
+  // TODO(https://crbug.com/80374): Consider making SignedExchangeHandler
+  // independent from DataPipe to make it easy to port it in //net.
+  explicit SignedExchangeHandler(mojo::ScopedDataPipeConsumerHandle body);
+
+  ~SignedExchangeHandler() override;
+
+  // TODO(https://crbug.com/80374): Currently SignedExchangeHandler always calls
+  // found_callback and then calls finish_callback after reading the all buffer.
+  // Need to redesign this callback model when we will introduce
+  // SignedExchangeHandler::Reader class to read the body and introduce the
+  // cert verification.
+  void GetHTTPExchange(ExchangeFoundCallback found_callback,
+                       ExchangeFinishedCallback finish_callback);
+
+ private:
+  // mojo::Common::DataPipeDrainer::Client
+  void OnDataAvailable(const void* data, size_t num_bytes) override;
+  void OnDataComplete() override;
+
+  // Called from |data_producer_|.
+  void OnDataWritten(MojoResult result);
+
+  mojo::ScopedDataPipeConsumerHandle body_;
+  std::unique_ptr<mojo::common::DataPipeDrainer> drainer_;
+  ExchangeFoundCallback found_callback_;
+  ExchangeFinishedCallback finish_callback_;
+  std::string original_body_string_;
+  std::unique_ptr<mojo::StringDataPipeProducer> data_producer_;
+
+  DISALLOW_COPY_AND_ASSIGN(SignedExchangeHandler);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_LOADER_SIGNED_EXCHANGE_HANDLER_H_

content/browser/loader/url_loader_request_handler.cc

@@ -16,7 +16,8 @@ URLLoaderRequestHandler::MaybeCreateSubresourceLoaderParams() {
 bool URLLoaderRequestHandler::MaybeCreateLoaderForResponse(
     const network::ResourceResponseHead& response,
     network::mojom::URLLoaderPtr* loader,
-    network::mojom::URLLoaderClientRequest* client_request) {
+    network::mojom::URLLoaderClientRequest* client_request,
+    ThrottlingURLLoader* url_loader) {
   return false;
 }
 

content/browser/loader/url_loader_request_handler.h

@@ -19,6 +19,7 @@ namespace content {
 class ResourceContext;
 struct ResourceRequest;
 struct SubresourceLoaderParams;
+class ThrottlingURLLoader;
 
 using StartLoaderCallback =
     base::OnceCallback<void(network::mojom::URLLoaderRequest request,
@@ -56,10 +57,17 @@ class CONTENT_EXPORT URLLoaderRequestHandler {
   // The URLLoader interface pointer is returned in the |loader| parameter.
   // The interface request for the URLLoaderClient is returned in the
   // |client_request| parameter.
+  // The |url_loader| points to the ThrottlingURLLoader that currently controls
+  // the request. It can be optionally consumed to get the current
+  // URLLoaderClient and URLLoader so that the implementation can rebind them to
+  // intercept the inflight loading if necessary.  Note that the |url_loader|
+  // will be reset after this method is called, which will also drop the
+  // URLLoader held by |url_loader_| if it is not unbound yet.
   virtual bool MaybeCreateLoaderForResponse(
       const network::ResourceResponseHead& response,
       network::mojom::URLLoaderPtr* loader,
-      network::mojom::URLLoaderClientRequest* client_request);
+      network::mojom::URLLoaderClientRequest* client_request,
+      ThrottlingURLLoader* url_loader);
 };
 
 }  // namespace content

content/browser/loader/web_package_loader.cc

+// Copyright 2018 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 "content/browser/loader/web_package_loader.h"
+
+#include "base/feature_list.h"
+#include "base/strings/stringprintf.h"
+#include "content/browser/loader/signed_exchange_handler.h"
+#include "content/public/common/content_features.h"
+#include "net/http/http_util.h"
+
+namespace content {
+
+namespace {
+
+net::RedirectInfo CreateRedirectInfo(const GURL& new_url) {
+  net::RedirectInfo redirect_info;
+  redirect_info.new_url = new_url;
+  redirect_info.new_method = "GET";
+  redirect_info.status_code = 302;
+  redirect_info.new_site_for_cookies = redirect_info.new_url;
+  return redirect_info;
+}
+
+}  // namespace
+
+class WebPackageLoader::ResponseTimingInfo {
+ public:
+  explicit ResponseTimingInfo(const network::ResourceResponseHead& response)
+      : request_start_(response.request_start),
+        response_start_(response.response_start),
+        request_time_(response.request_time),
+        response_time_(response.response_time),
+        load_timing_(response.load_timing) {}
+
+  network::ResourceResponseHead CreateRedirectResponseHead() const {
+    network::ResourceResponseHead response_head;
+    response_head.encoded_data_length = 0;
+    std::string buf(base::StringPrintf("HTTP/1.1 %d %s\r\n", 302, "Found"));
+    response_head.headers = new net::HttpResponseHeaders(
+        net::HttpUtil::AssembleRawHeaders(buf.c_str(), buf.size()));
+    response_head.encoded_data_length = 0;
+    response_head.request_start = request_start_;
+    response_head.response_start = response_start_;
+    response_head.request_time = request_time_;
+    response_head.response_time = response_time_;
+    response_head.load_timing = load_timing_;
+    return response_head;
+  }
+
+ private:
+  const base::TimeTicks request_start_;
+  const base::TimeTicks response_start_;
+  const base::Time request_time_;
+  const base::Time response_time_;
+  const net::LoadTimingInfo load_timing_;
+
+  DISALLOW_COPY_AND_ASSIGN(ResponseTimingInfo);
+};
+
+WebPackageLoader::WebPackageLoader(
+    const network::ResourceResponseHead& original_response,
+    network::mojom::URLLoaderClientPtr forwarding_client,
+    network::mojom::URLLoaderClientEndpointsPtr endpoints)
+    : original_response_timing_info_(
+          base::MakeUnique<ResponseTimingInfo>(original_response)),
+      forwarding_client_(std::move(forwarding_client)),
+      url_loader_client_binding_(this),
+      weak_factory_(this) {
+  DCHECK(base::FeatureList::IsEnabled(features::kSignedHTTPExchange));
+  url_loader_.Bind(std::move(endpoints->url_loader));
+
+  if (!base::FeatureList::IsEnabled(features::kNetworkService)) {
+    // We don't propagate the response to the navigation request and its
+    // throttles, therefore we need to call this here internally in order to
+    // move it forward.
+    // TODO(https://crbug.com/791049): Remove this when NetworkService is
+    // enabled by default.
+    url_loader_->ProceedWithResponse();
+  }
+
+  // Bind the endpoint with |this| to get the body DataPipe.
+  url_loader_client_binding_.Bind(std::move(endpoints->url_loader_client));
+
+  // |client_| will be bound with a forwarding client by ConnectToClient().
+  pending_client_request_ = mojo::MakeRequest(&client_);
+}
+
+WebPackageLoader::~WebPackageLoader() = default;
+
+void WebPackageLoader::OnReceiveResponse(
+    const network::ResourceResponseHead& response_head,
+    const base::Optional<net::SSLInfo>& ssl_info,
+    network::mojom::DownloadedTempFilePtr downloaded_file) {
+  // Must not be called because this WebPackageLoader and the client endpoints
+  // were bound after OnReceiveResponse() is called.
+  NOTREACHED();
+}
+
+void WebPackageLoader::OnReceiveRedirect(
+    const net::RedirectInfo& redirect_info,
+    const network::ResourceResponseHead& response_head) {
+  // Must not be called because this WebPackageLoader and the client endpoints
+  // were bound after OnReceiveResponse() is called.
+  NOTREACHED();
+}
+
+void WebPackageLoader::OnDataDownloaded(int64_t data_len,
+                                        int64_t encoded_data_len) {
+  // Must not be called because this WebPackageLoader and the client endpoints
+  // were bound after OnReceiveResponse() is called.
+  NOTREACHED();
+}
+
+void WebPackageLoader::OnUploadProgress(int64_t current_position,
+                                        int64_t total_size,
+                                        OnUploadProgressCallback ack_callback) {
+  // Must not be called because this WebPackageLoader and the client endpoints
+  // were bound after OnReceiveResponse() is called.
+  NOTREACHED();
+}
+
+void WebPackageLoader::OnReceiveCachedMetadata(
+    const std::vector<uint8_t>& data) {
+  // Curerntly CachedMetadata for WebPackage is not supported.
+  NOTREACHED();
+}
+
+void WebPackageLoader::OnTransferSizeUpdated(int32_t transfer_size_diff) {
+  // TODO(https://crbug.com/80374): Implement this to progressively update the
+  // encoded data length in DevTools.
+}
+
+void WebPackageLoader::OnStartLoadingResponseBody(
+    mojo::ScopedDataPipeConsumerHandle body) {
+  signed_exchange_handler_ =
+      base::MakeUnique<SignedExchangeHandler>(std::move(body));
+  signed_exchange_handler_->GetHTTPExchange(
+      base::BindOnce(&WebPackageLoader::OnHTTPExchangeFound,
+                     weak_factory_.GetWeakPtr()),
+      base::BindOnce(&WebPackageLoader::OnHTTPExchangeFinished,
+                     weak_factory_.GetWeakPtr()));
+}
+
+void WebPackageLoader::OnComplete(
+    const network::URLLoaderCompletionStatus& status) {
+  // TODO(https://crbug.com/80374): Copy the data length information and pass to
+  // |client_| when OnHTTPExchangeFinished() is called.
+}
+
+void WebPackageLoader::FollowRedirect() {
+  NOTREACHED();
+}
+
+void WebPackageLoader::ProceedWithResponse() {
+  // TODO(https://crbug.com/791049): Remove this when NetworkService is
+  // enabled by default.
+  DCHECK(!base::FeatureList::IsEnabled(features::kNetworkService));
+  DCHECK(pending_body_.is_valid());
+  DCHECK(client_);
+  client_->OnStartLoadingResponseBody(std::move(pending_body_));
+  if (pending_completion_status_) {
+    client_->OnComplete(*pending_completion_status_);
+  }
+}
+
+void WebPackageLoader::SetPriority(net::RequestPriority priority,
+                                   int intra_priority_value) {
+  // TODO(https://crbug.com/80374): Implement this.
+}
+
+void WebPackageLoader::PauseReadingBodyFromNet() {
+  // TODO(https://crbug.com/80374): Implement this.
+}
+
+void WebPackageLoader::ResumeReadingBodyFromNet() {
+  // TODO(https://crbug.com/80374): Implement this.
+}
+
+void WebPackageLoader::ConnectToClient(
+    network::mojom::URLLoaderClientPtr client) {
+  DCHECK(pending_client_request_.is_pending());
+  mojo::FuseInterface(std::move(pending_client_request_),
+                      client.PassInterface());
+}
+
+void WebPackageLoader::OnHTTPExchangeFound(
+    const GURL& request_url,
+    const std::string& request_method,
+    const network::ResourceResponseHead& resource_response,
+    base::Optional<net::SSLInfo> ssl_info,
+    mojo::ScopedDataPipeConsumerHandle body) {
+  // TODO(https://crbug.com/80374): Handle no-GET request_method as a error.
+  DCHECK(original_response_timing_info_);
+  forwarding_client_->OnReceiveRedirect(
+      CreateRedirectInfo(request_url),
+      std::move(original_response_timing_info_)->CreateRedirectResponseHead());
+  forwarding_client_->OnComplete(network::URLLoaderCompletionStatus(net::OK));
+  forwarding_client_.reset();
+
+  client_->OnReceiveResponse(resource_response, std::move(ssl_info),
+                             nullptr /* downloaded_file */);
+
+  if (!base::FeatureList::IsEnabled(features::kNetworkService)) {
+    // Need to wait until ProceedWithResponse() is called.
+    pending_body_ = std::move(body);
+  } else {
+    client_->OnStartLoadingResponseBody(std::move(body));
+  }
+}
+
+void WebPackageLoader::OnHTTPExchangeFinished(
+    const network::URLLoaderCompletionStatus& status) {
+  if (pending_body_.is_valid()) {
+    DCHECK(!base::FeatureList::IsEnabled(features::kNetworkService));
+    // If ProceedWithResponse() was not called yet, need to call OnComplete()
+    // after ProceedWithResponse() is called.
+    pending_completion_status_ = status;
+  } else {
+    client_->OnComplete(status);
+  }
+}
+
+}  // namespace content

content/browser/loader/web_package_loader.h

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_LOADER_WEB_PACKAGE_LOADER_H_
+#define CONTENT_BROWSER_LOADER_WEB_PACKAGE_LOADER_H_
+
+#include "base/optional.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "net/ssl/ssl_info.h"
+#include "net/url_request/redirect_info.h"
+#include "services/network/public/interfaces/url_loader.mojom.h"
+
+namespace content {
+
+class SignedExchangeHandler;
+
+// WebPackageLoader handles an origin-signed HTTP exchange response. It is
+// created when a WebPackageRequestHandler recieves an origin-signed HTTP
+// exchange response, and is owned by the handler until the StartLoaderCallback
+// of WebPackageRequestHandler::StartResponse is called. After that, it is
+// owned by the URLLoader mojo endpoint.
+class WebPackageLoader final : public network::mojom::URLLoaderClient,
+                               public network::mojom::URLLoader {
+ public:
+  WebPackageLoader(const network::ResourceResponseHead& original_response,
+                   network::mojom::URLLoaderClientPtr forwarding_client,
+                   network::mojom::URLLoaderClientEndpointsPtr endpoints);
+  ~WebPackageLoader() override;
+
+  // network::mojom::URLLoaderClient implementation
+  // Only OnStartLoadingResponseBody() and OnComplete() are called.
+  void OnReceiveResponse(
+      const network::ResourceResponseHead& response_head,
+      const base::Optional<net::SSLInfo>& ssl_info,
+      network::mojom::DownloadedTempFilePtr downloaded_file) override;
+  void OnReceiveRedirect(
+      const net::RedirectInfo& redirect_info,
+      const network::ResourceResponseHead& response_head) override;
+  void OnDataDownloaded(int64_t data_len, int64_t encoded_data_len) override;
+  void OnUploadProgress(int64_t current_position,
+                        int64_t total_size,
+                        OnUploadProgressCallback ack_callback) override;
+  void OnReceiveCachedMetadata(const std::vector<uint8_t>& data) override;
+  void OnTransferSizeUpdated(int32_t transfer_size_diff) override;
+  void OnStartLoadingResponseBody(
+      mojo::ScopedDataPipeConsumerHandle body) override;
+  void OnComplete(const network::URLLoaderCompletionStatus& status) override;
+
+  // network::mojom::URLLoader implementation
+  void FollowRedirect() override;
+  void ProceedWithResponse() override;
+  void SetPriority(net::RequestPriority priority,
+                   int intra_priority_value) override;
+  void PauseReadingBodyFromNet() override;
+  void ResumeReadingBodyFromNet() override;
+
+  void ConnectToClient(network::mojom::URLLoaderClientPtr client);
+
+ private:
+  class ResponseTimingInfo;
+
+  // Called from |signed_exchange_handler_| when it finds an origin-signed HTTP
+  // exchange.
+  void OnHTTPExchangeFound(
+      const GURL& request_url,
+      const std::string& request_method,
+      const network::ResourceResponseHead& resource_response,
+      base::Optional<net::SSLInfo> ssl_info,
+      mojo::ScopedDataPipeConsumerHandle body);
+
+  // Called from |signed_exchange_handler_| when it finished sending the
+  // payload of the origin-signed HTTP response.
+  void OnHTTPExchangeFinished(const network::URLLoaderCompletionStatus& status);
+
+  // This timing info is used to create a dummy redirect response.
+  std::unique_ptr<const ResponseTimingInfo> original_response_timing_info_;
+
+  // This client is alive until OnHTTPExchangeFound() is called.
+  network::mojom::URLLoaderClientPtr forwarding_client_;
+
+  // This |url_loader_| is the pointer of the network URL loader.
+  network::mojom::URLLoaderPtr url_loader_;
+  // This binding connects |this| with the network URL loader.
+  mojo::Binding<network::mojom::URLLoaderClient> url_loader_client_binding_;
+
+  // This is pending until connected by ConnectToClient().
+  network::mojom::URLLoaderClientPtr client_;
+
+  // This URLLoaderClientRequest is used by ConnectToClient() to connect
+  // |client_|.
+  network::mojom::URLLoaderClientRequest pending_client_request_;
+
+  std::unique_ptr<SignedExchangeHandler> signed_exchange_handler_;
+
+  // This is used to keep the DataPipe until ProceedWithResponse() is called.
+  mojo::ScopedDataPipeConsumerHandle pending_body_;
+  // This is used to keep the status until ProceedWithResponse() is called.
+  base::Optional<network::URLLoaderCompletionStatus> pending_completion_status_;
+
+  base::WeakPtrFactory<WebPackageLoader> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebPackageLoader);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_LOADER_WEB_PACKAGE_LOADER_H_

content/browser/loader/web_package_request_handler.cc

+// Copyright 2017 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 "content/browser/loader/web_package_request_handler.h"
+
+#include "base/bind.h"
+#include "base/feature_list.h"
+#include "content/browser/loader/web_package_loader.h"
+#include "content/common/throttling_url_loader.h"
+#include "content/public/common/content_features.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+#include "net/http/http_response_headers.h"
+#include "services/network/public/cpp/resource_response.h"
+#include "services/network/public/interfaces/url_loader.mojom.h"
+
+namespace content {
+
+// static
+bool WebPackageRequestHandler::IsSupportedMimeType(
+    const std::string& mime_type) {
+  DCHECK(base::FeatureList::IsEnabled(features::kSignedHTTPExchange));
+  return mime_type == "application/http-exchange+cbor";
+}
+
+WebPackageRequestHandler::WebPackageRequestHandler() : weak_factory_(this) {
+  DCHECK(base::FeatureList::IsEnabled(features::kSignedHTTPExchange));
+}
+
+WebPackageRequestHandler::~WebPackageRequestHandler() = default;
+
+void WebPackageRequestHandler::MaybeCreateLoader(
+    const network::ResourceRequest& resource_request,
+    ResourceContext* resource_context,
+    LoaderCallback callback) {
+  // TODO(https://crbug.com/80374): Ask WebPackageFetchManager to get the
+  // ongoing matching SignedExchangeHandler which was created by a
+  // WebPackagePrefetcher.
+
+  if (!web_package_loader_) {
+    std::move(callback).Run(StartLoaderCallback());
+    return;
+  }
+
+  std::move(callback).Run(base::BindOnce(
+      &WebPackageRequestHandler::StartResponse, weak_factory_.GetWeakPtr()));
+}
+
+bool WebPackageRequestHandler::MaybeCreateLoaderForResponse(
+    const network::ResourceResponseHead& response,
+    network::mojom::URLLoaderPtr* loader,
+    network::mojom::URLLoaderClientRequest* client_request,
+    ThrottlingURLLoader* url_loader) {
+  std::string mime_type;
+  if (response.was_fetched_via_service_worker || !response.headers ||
+      !response.headers->GetMimeType(&mime_type) ||
+      !IsSupportedMimeType(mime_type)) {
+    return false;
+  }
+
+  network::mojom::URLLoaderClientPtr client;
+  *client_request = mojo::MakeRequest(&client);
+
+  // TODO(https://crbug.com/80374): Consider creating a new ThrottlingURLLoader
+  // or reusing the existing ThrottlingURLLoader by reattaching URLLoaderClient,
+  // to support SafeBrowsing checking of the content of the WebPackage.
+  web_package_loader_ = base::MakeUnique<WebPackageLoader>(
+      response, std::move(client), url_loader->Unbind());
+  return true;
+}
+
+void WebPackageRequestHandler::StartResponse(
+    network::mojom::URLLoaderRequest request,
+    network::mojom::URLLoaderClientPtr client) {
+  web_package_loader_->ConnectToClient(std::move(client));
+  mojo::MakeStrongBinding(std::move(web_package_loader_), std::move(request));
+}
+
+}  // namespace content

content/browser/loader/web_package_request_handler.h

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_LOADER_WEB_PACKAGE_REQUEST_HANDLER_H_
+#define CONTENT_BROWSER_LOADER_WEB_PACKAGE_REQUEST_HANDLER_H_
+
+#include "base/memory/weak_ptr.h"
+#include "content/browser/loader/url_loader_request_handler.h"
+
+namespace content {
+
+class WebPackageLoader;
+
+class WebPackageRequestHandler final : public URLLoaderRequestHandler {
+ public:
+  static bool IsSupportedMimeType(const std::string& mime_type);
+
+  WebPackageRequestHandler();
+  ~WebPackageRequestHandler() override;
+
+  // URLLoaderRequestHandler implementation
+  void MaybeCreateLoader(const network::ResourceRequest& resource_request,
+                         ResourceContext* resource_context,
+                         LoaderCallback callback) override;
+  bool MaybeCreateLoaderForResponse(
+      const network::ResourceResponseHead& response,
+      network::mojom::URLLoaderPtr* loader,
+      network::mojom::URLLoaderClientRequest* client_request,
+      ThrottlingURLLoader* url_loader) override;
+
+ private:
+  void StartResponse(network::mojom::URLLoaderRequest request,
+                     network::mojom::URLLoaderClientPtr client);
+
+  // Valid after MaybeCreateLoaderForResponse intercepts the request and until
+  // the loader is re-bound to the new client for the redirected request in
+  // StartResponse.
+  std::unique_ptr<WebPackageLoader> web_package_loader_;
+
+  base::WeakPtrFactory<WebPackageRequestHandler> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebPackageRequestHandler);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_LOADER_WEB_PACKAGE_REQUEST_HANDLER_H_

content/public/common/browser_side_navigation_policy.cc

@@ -22,7 +22,8 @@ bool IsNavigationMojoResponseEnabled() {
   if (!IsBrowserSideNavigationEnabled())
     return false;
 
-  return base::FeatureList::IsEnabled(features::kNavigationMojoResponse);
+  return base::FeatureList::IsEnabled(features::kNavigationMojoResponse) ||
+         base::FeatureList::IsEnabled(features::kSignedHTTPExchange);
 }
 
 }  // namespace content

third_party/WebKit/LayoutTests/TestExpectations

@@ -96,6 +96,8 @@ crbug.com/805049 virtual/spv175/paint/invalidation/scroll/fixed-scroll-simple.ht
 crbug.com/417782 virtual/spv175/compositing/overflow/border-radius-composited-subframe.html [ Failure ]
 crbug.com/417782 virtual/spv175/paint/invalidation/window-resize/window-resize-vertical-writing-mode.html [ Crash ]
 
+crbug.com/803774 http/tests/loading/htxg/ [ Skip ]
+
 ########## Ref tests can't be rebaselined ##########
 crbug.com/504613 crbug.com/524248 [ Mac ] paint/images/image-backgrounds-not-antialiased.html [ Failure ]
 

third_party/WebKit/LayoutTests/VirtualTestSuites

@@ -643,5 +643,15 @@
     "prefix": "unified-autoplay",
     "base": "external/wpt/feature-policy",
     "args": ["--autoplay-policy=document-user-activation-required"]
+  },
+  {
+    "prefix": "htxg",
+    "base": "http/tests/loading/htxg/",
+    "args": ["--enable-features=SignedHTTPExchange"]
+  },
+  {
+    "prefix": "htxg-with-network-service",
+    "base": "http/tests/loading/htxg/",
+    "args": ["--enable-features=SignedHTTPExchange,NetworkService"]
   }
 ]

third_party/WebKit/LayoutTests/http/tests/loading/htxg/origin-signed-response.html

+<!DOCTYPE html>
+<title>Location of origin-signed HTTP response</title>
+<script src="../../resources/testharness.js"></script>
+<script src="../../resources/testharnessreport.js"></script>
+<script src="../../resources/get-host-info.js?pipe=sub"></script>
+<body>
+<script>
+function with_iframe(url) {
+  return new Promise(function(resolve) {
+      const frame = document.createElement('iframe');
+      frame.src = url;
+      frame.onload = function() { resolve(frame); };
+      document.body.appendChild(frame);
+    });
+}
+
+promise_test(function(t) {
+  const url = 'resources/origin-signed-response-iframe.php';
+  return with_iframe(url)
+    .then((frame) => {
+      var channel = new MessageChannel();
+      var promise =
+          new Promise((resolve) => { channel.port1.onmessage = resolve; });
+      frame.contentWindow.postMessage(
+        {port: channel.port2}, '*', [channel.port2]);
+      return promise;
+    })
+    .then((event) => {
+      // TODO(https://crbug.com/80374): Currently this URL is hard coded in
+      // SignedExchangeHandler.
+      assert_equals(event.data.location, 'https://example.com/test.html');
+    });
+}, 'Location of origin-signed HTTP response');
+</script>
+</body>
+

third_party/WebKit/LayoutTests/http/tests/loading/htxg/resources/origin-signed-response-iframe.php

+<?php
+header('Content-Type: application/http-exchange+cbor');
+?>
+<!DOCTYPE html>
+<body>
+<script>
+window.addEventListener('message', (event) => {
+  event.data.port.postMessage({location: document.location.href});
+}, false);
+</script>
+hello<br>
+world
+</body>

third_party/WebKit/LayoutTests/virtual/htxg-with-network-service/http/tests/loading/htxg/README.txt

+This directory is for testing the SignedHTTPExchange feature with the Network
+Service.

third_party/WebKit/LayoutTests/virtual/htxg/http/tests/loading/htxg/README.txt

+This directory is for testing the SignedHTTPExchange feature.