Adding Frame Accept header to Search prefetch requests

This also refactors the content/ accept header code to be in public
along with the signed exchange accept header suffix.

Bug: 1138648
Change-Id: Idf3f5d4f8b3034e301318bdb29d509ee46bc3d10
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2533331
Commit-Queue: Ryan Sturm <ryansturm@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828037}

chrome/browser/prefetch/search_prefetch/search_prefetch_service.cc

@@ -18,6 +18,7 @@
 #include "components/search_engines/template_url_service.h"
 #include "components/variations/net/variations_http_headers.h"
 #include "content/public/browser/browser_context.h"
+#include "content/public/browser/frame_accept_header.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/storage_partition.h"
 #include "content/public/common/content_constants.h"
@@ -100,6 +101,9 @@ void SearchPrefetchService::PrefetchRequest::StartPrefetchRequest(
       prefetch_url_, variations::InIncognito::kNo, resource_request.get());
   resource_request->headers.SetHeader(content::kCorsExemptPurposeHeaderName,
                                       "prefetch");
+  resource_request->headers.SetHeader(
+      net::HttpRequestHeaders::kAccept,
+      content::FrameAcceptHeaderValue(/*allow_sxg_responses=*/true, profile));
   // TODO(ryansturm): Find other headers that may need to be set.
   // https://crbug.com/1138648
 

chrome/browser/prefetch/search_prefetch/search_prefetch_service_browsertest.cc

@@ -452,6 +452,9 @@ IN_PROC_BROWSER_TEST_F(SearchPrefetchServiceEnabledBrowserTest,
   EXPECT_EQ(1u, search_server_requests().size());
   EXPECT_NE(std::string::npos,
             search_server_requests()[0].GetURL().spec().find(search_terms));
+  auto headers = search_server_requests()[0].headers;
+  ASSERT_TRUE(base::Contains(headers, "Accept"));
+  EXPECT_TRUE(base::Contains(headers["Accept"], "text/html"));
   EXPECT_EQ(1u, search_server_request_count());
   EXPECT_EQ(1u, search_server_prefetch_request_count());
 

content/browser/loader/navigation_url_loader_impl.cc

@@ -53,6 +53,7 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/download_utils.h"
+#include "content/public/browser/frame_accept_header.h"
 #include "content/public/browser/navigation_ui_data.h"
 #include "content/public/browser/shared_cors_origin_access_list.h"
 #include "content/public/browser/ssl_status.h"
@@ -278,21 +279,6 @@ void UnknownSchemeCallback(
           handled_externally ? net::ERR_ABORTED : net::ERR_UNKNOWN_URL_SCHEME));
 }
 
-const char* FrameAcceptHeaderValue() {
-#if BUILDFLAG(ENABLE_AV1_DECODER)
-  static const char kFrameAcceptHeaderValueWithAvif[] =
-      "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,"
-      "image/webp,image/apng,*/*;q=0.8";
-  static const char* accept_value =
-      base::FeatureList::IsEnabled(blink::features::kAVIF)
-          ? kFrameAcceptHeaderValueWithAvif
-          : network::kFrameAcceptHeaderValue;
-  return accept_value;
-#else
-  return network::kFrameAcceptHeaderValue;
-#endif
-}
-
 }  // namespace
 
 // TODO(kinuko): Fix the method ordering and move these methods after the ctor.
@@ -361,13 +347,9 @@ void NavigationURLLoaderImpl::Start(
             std::move(factory));
   }
 
-  std::string accept_header_value = FrameAcceptHeaderValue();
-  if (signed_exchange_utils::IsSignedExchangeHandlingEnabled(
-          browser_context_)) {
-    accept_header_value.append(kAcceptHeaderSignedExchangeSuffix);
-  }
-  resource_request_->headers.SetHeader(net::HttpRequestHeaders::kAccept,
-                                       accept_header_value);
+  resource_request_->headers.SetHeader(
+      net::HttpRequestHeaders::kAccept,
+      FrameAcceptHeaderValue(/*allow_sxg_responses=*/true, browser_context_));
 
   // Requests to WebUI scheme won't get redirected to/from other schemes
   // or be intercepted, so we just let it go here.
@@ -741,10 +723,12 @@ void NavigationURLLoaderImpl::FollowRedirectInternal(
 
   // Don't send Accept: application/signed-exchange for fallback redirects.
   if (redirect_info_.is_signed_exchange_fallback_redirect) {
+    std::string header_value =
+        FrameAcceptHeaderValue(/*allow_sxg_responses=*/false, browser_context_);
     url_loader_modified_headers_.SetHeader(net::HttpRequestHeaders::kAccept,
-                                           FrameAcceptHeaderValue());
+                                           header_value);
     resource_request_->headers.SetHeader(net::HttpRequestHeaders::kAccept,
-                                         FrameAcceptHeaderValue());
+                                         header_value);
   }
 
   Restart();

content/public/browser/BUILD.gn

@@ -154,6 +154,8 @@ source_set("browser_sources") {
     "file_url_loader.h",
     "focused_node_details.h",
     "font_list_async.h",
+    "frame_accept_header.cc",
+    "frame_accept_header.h",
     "frame_service_base.h",
     "generated_code_cache_settings.h",
     "global_request_id.h",

content/public/browser/frame_accept_header.cc

+// Copyright 2020 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/public/browser/frame_accept_header.h"
+
+#include "base/feature_list.h"
+#include "build/build_config.h"
+#include "content/browser/web_package/signed_exchange_consts.h"
+#include "content/browser/web_package/signed_exchange_utils.h"
+#include "services/network/public/cpp/constants.h"
+#include "third_party/blink/public/common/features.h"
+
+namespace content {
+
+std::string FrameAcceptHeaderValue(bool allow_sxg_responses,
+                                   BrowserContext* browser_context) {
+  std::string header_value = network::kFrameAcceptHeaderValue;
+#if BUILDFLAG(ENABLE_AV1_DECODER)
+  static const char kFrameAcceptHeaderValueWithAvif[] =
+      "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,"
+      "image/webp,image/apng,*/*;q=0.8";
+  if (base::FeatureList::IsEnabled(blink::features::kAVIF))
+    header_value = kFrameAcceptHeaderValueWithAvif;
+#endif
+  if (allow_sxg_responses &&
+      content::signed_exchange_utils::IsSignedExchangeHandlingEnabled(
+          browser_context)) {
+    header_value.append(kAcceptHeaderSignedExchangeSuffix);
+  }
+  return header_value;
+}
+
+}  // namespace content

content/public/browser/frame_accept_header.h

+// Copyright 2020 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_PUBLIC_BROWSER_FRAME_ACCEPT_HEADER_H_
+#define CONTENT_PUBLIC_BROWSER_FRAME_ACCEPT_HEADER_H_
+
+#include <string>
+
+#include "content/common/content_export.h"
+
+namespace content {
+class BrowserContext;
+
+// The value that should be set for the "Accept" header for frame navigations.
+// Includes signed exchange and image decoder information (when applicable) that
+// are not available from the network service. This may also accept signed
+// exchange responses when |allow_sxg_responses| is true.
+CONTENT_EXPORT std::string FrameAcceptHeaderValue(
+    bool allow_sxg_responses,
+    BrowserContext* browser_context);
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_FRAME_ACCEPT_HEADER_H_