Add 'accept' and 'upgrade-insecure-request' headers to prefetch

requests.

These headers will be added to all prefetch requests in order to match
the headers added to default mainframe requests.

(cherry picked from commit 7f00fb9)

Bug: 1318193
Change-Id: I9063ee08adcd86e0e13887e6edabbe09fa5c9a1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3597448
Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Commit-Queue: Max Curran <curranmax@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#994434}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3611762
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Max Curran <curranmax@chromium.org>
Cr-Commit-Position: refs/branch-heads/5005@{#206}
Cr-Branched-From: 5b4d945-refs/heads/main@{#992738}

chrome/browser/prefetch/prefetch_proxy/prefetch_proxy_tab_helper.cc

@@ -43,6 +43,7 @@
 #include "components/search_engines/template_url_service.h"
 #include "components/version_info/version_info.h"
 #include "content/public/browser/browser_context.h"
+#include "content/public/browser/frame_accept_header.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/network_service_instance.h"
 #include "content/public/browser/render_frame_host.h"
@@ -846,6 +847,10 @@ void PrefetchProxyTabHelper::StartSinglePrefetch() {
       prefetch_container->GetPrefetchType().IsProxyRequired()
           ? prefetch::headers::kSecPurposePrefetchAnonymousClientIpHeaderValue
           : prefetch::headers::kSecPurposePrefetchHeaderValue);
+  request->headers.SetHeader(
+      net::HttpRequestHeaders::kAccept,
+      content::FrameAcceptHeaderValue(/*allow_sxg_responses=*/true, profile_));
+  request->headers.SetHeader("Upgrade-Insecure-Requests", "1");
   // Remove the user agent header if it was set so that the network context's
   // default is used.
   request->headers.RemoveHeader("User-Agent");

chrome/browser/prefetch/prefetch_proxy/prefetch_proxy_tab_helper_unittest.cc

@@ -27,6 +27,7 @@
 #include "chrome/test/base/chrome_render_view_host_test_harness.h"
 #include "components/prefs/pref_service.h"
 #include "content/public/browser/browser_context.h"
+#include "content/public/browser/frame_accept_header.h"
 #include "content/public/browser/service_worker_context.h"
 #include "content/public/browser/storage_partition.h"
 #include "content/public/browser/web_contents.h"
@@ -695,7 +696,7 @@ TEST_F(PrefetchProxyTabHelperTest, WrongWebContents) {
       "PrefetchProxy.Prefetch.Mainframe.TotalRedirects", 0);
 }
 
-TEST_F(PrefetchProxyTabHelperTest, HasPurposePrefetchHeader) {
+TEST_F(PrefetchProxyTabHelperTest, HasExplicitHeaders) {
   base::HistogramTester histogram_tester;
 
   NavigateSomewhere();
@@ -704,7 +705,15 @@ TEST_F(PrefetchProxyTabHelperTest, HasPurposePrefetchHeader) {
   MakeNavigationPrediction(web_contents(), doc_url, {prediction_url});
 
   VerifyCommonRequestState(prediction_url);
+
+  // Checks that headers added explicitly by |PrefetchProxyTabHelper| were
+  // included.
   EXPECT_EQ(RequestHeader("Purpose"), "prefetch");
+  EXPECT_EQ(RequestHeader("Sec-Purpose"), "prefetch;anonymous-client-ip");
+  EXPECT_EQ(
+      RequestHeader("Accept"),
+      content::FrameAcceptHeaderValue(/*allow_sxg_responses=*/true, profile()));
+  EXPECT_EQ(RequestHeader("Upgrade-Insecure-Requests"), "1");
 
   EXPECT_EQ(predicted_urls_count(), 1U);
   EXPECT_EQ(prefetch_eligible_count(), 1U);