[Downloads] Set the Referrer header for resumed requests.

content/browser/download/download_item_impl.cc

 // Copyright (c) 2012 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.
 
 // File method ordering: Methods in this file are in the same order as
 // in download_item_impl.h, with the following exception: The public
 // interface Start is placed in chronological order with the other
 // (private) routines that together define a DownloadItem's state
 // transitions as the download progresses.  See "Download progression
 // cascade" later in this file.
@@ skipping 792 matching lines @@
         " reason = %s"
         " paused = %c"
         " resume_mode = %s"
         " auto_resume_count = %d"
         " danger = %d"
         " all_data_saved = %c"
         " last_modified = '%s'"
         " etag = '%s'"
         " has_download_file = %s"
         " url_chain = \n\t\"%s\"\n\t"
-        " current_path = \"%" PRFilePath
-        "\"\n\t"
-        " target_path = \"%" PRFilePath "\"",
+        " current_path = \"%" PRFilePath "\"\n\t"
+        " target_path = \"%" PRFilePath "\""
+        " referrer = \"%s\"",
         GetTotalBytes(),
         GetReceivedBytes(),
         DownloadInterruptReasonToString(last_reason_).c_str(),
         IsPaused() ? 'T' : 'F',
         DebugResumeModeString(GetResumeMode()),
         auto_resume_count_,
         GetDangerType(),
         AllDataSaved() ? 'T' : 'F',
         GetLastModifiedTime().c_str(),
         GetETag().c_str(),
         download_file_.get() ? "true" : "false",
         url_list.c_str(),
         GetFullPath().value().c_str(),
-        GetTargetFilePath().value().c_str());
+        GetTargetFilePath().value().c_str(),
+        GetReferrerUrl().spec().c_str());
   } else {
     description += base::StringPrintf(" url = \"%s\"", url_list.c_str());
   }
 
   description += " }";
 
   return description;
 }
 
 DownloadItemImpl::ResumeMode DownloadItemImpl::GetResumeMode() const {
@@ skipping 1067 matching lines @@
   std::unique_ptr<DownloadUrlParameters> download_params(
       new DownloadUrlParameters(GetURL(), -1, -1, -1,
                                 GetBrowserContext()->GetResourceContext()));
   download_params->set_file_path(GetFullPath());
   download_params->set_offset(GetReceivedBytes());
   download_params->set_last_modified(GetLastModifiedTime());
   download_params->set_etag(GetETag());
   download_params->set_hash_of_partial_file(hash_);
   download_params->set_hash_state(std::move(hash_state_));
 
+  // Note that resumed downloads disallow redirects. Hence the referrer URL
+  // (which is the contents of the Referer header for the last download request)
+  // will only be sent to the URL returned by GetURL().
+  download_params->set_referrer(
+      Referrer(GetReferrerUrl(), blink::WebReferrerPolicyAlways));
+
   TransitionTo(RESUMING_INTERNAL);
   delegate_->ResumeInterruptedDownload(std::move(download_params), GetId());
   // Just in case we were interrupted while paused.
   is_paused_ = false;
 }
 
 // static
 DownloadItem::DownloadState DownloadItemImpl::InternalToExternalState(
     DownloadInternalState internal_state) {
   switch (internal_state) {
@@ skipping 163 matching lines @@
     case RESUME_MODE_USER_CONTINUE:
       return "USER_CONTINUE";
     case RESUME_MODE_USER_RESTART:
       return "USER_RESTART";
   }
   NOTREACHED() << "Unknown resume mode " << mode;
   return "unknown";
 }
 
 }  // namespace content