[downloads] Set initiator when handling downloads via a[download]

content/public/browser/download_url_parameters.h

Index: content/public/browser/download_url_parameters.h
diff --git a/content/public/browser/download_url_parameters.h b/content/public/browser/download_url_parameters.h
index d5c32d8dfb24b4a65f14a5fb60d3c8efa66b1d18..41b0ed637bdbb3dca8662e6c0309594f734e94f7 100644
--- a/content/public/browser/download_url_parameters.h
+++ b/content/public/browser/download_url_parameters.h
@@ -15,12 +15,14 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/optional.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/download_save_info.h"
 #include "content/public/common/referrer.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "storage/browser/blob/blob_data_handle.h"
 #include "url/gurl.h"
+#include "url/origin.h"
 
 namespace content {
 
@@ -107,6 +109,12 @@ class CONTENT_EXPORT DownloadUrlParameters {
     referrer_encoding_ = referrer_encoding;
   }
 
+  // The origin of the context which initiated the request. See
+  // net::URLRequest::initiator().
+  void set_initiator(const base::Optional<url::Origin>& initiator) {
+    initiator_ = initiator;
+  }
+
   // If this is a request for resuming an HTTP/S download, |last_modified|
   // should be the value of the last seen Last-Modified response header.
   void set_last_modified(const std::string& last_modified) {
@@ -210,6 +218,7 @@ class CONTENT_EXPORT DownloadUrlParameters {
   bool prefer_cache() const { return prefer_cache_; }
   const Referrer& referrer() const { return referrer_; }
   const std::string& referrer_encoding() const { return referrer_encoding_; }
+  const base::Optional<url::Origin>& initiator() const { return initiator_; }
 
   // These will be -1 if the request is not associated with a frame. See
   // the constructors for more.
@@ -257,6 +266,7 @@ class CONTENT_EXPORT DownloadUrlParameters {
   int64_t post_id_;
   bool prefer_cache_;
   Referrer referrer_;
+  base::Optional<url::Origin> initiator_;
   std::string referrer_encoding_;
   int render_process_host_id_;
   int render_view_host_routing_id_;