Teach URLRequest about initiator checks for First-Party-Only cookies.

content/child/web_url_loader_impl.cc

Index: content/child/web_url_loader_impl.cc
diff --git a/content/child/web_url_loader_impl.cc b/content/child/web_url_loader_impl.cc
index a668f1c7356fabb490587015d54e9187ac6d278a..d886cb0bd4a84bd32a139048878be376e01c3c38 100644
--- a/content/child/web_url_loader_impl.cc
+++ b/content/child/web_url_loader_impl.cc
@@ -43,6 +43,7 @@
 #include "net/ssl/ssl_connection_status_flags.h"
 #include "net/url_request/url_request_data_job.h"
 #include "third_party/WebKit/public/platform/WebHTTPLoadInfo.h"
+#include "third_party/WebKit/public/platform/WebSecurityOrigin.h"
 #include "third_party/WebKit/public/platform/WebTraceLocation.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/platform/WebURLError.h"
@@ -469,6 +470,7 @@ void WebURLLoaderImpl::Context::Start(const WebURLRequest& request,
   request_info.method = method;
   request_info.url = url;
   request_info.first_party_for_cookies = request.firstPartyForCookies();
+  request_info.request_initiator = request.requestorOrigin();
   referrer_policy_ = request.referrerPolicy();
   request_info.referrer = Referrer(referrer_url, referrer_policy_);
   request_info.headers = GetWebURLRequestHeaders(request);