Set 'ResourceRequest::requestorOrigin' in Blink.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index db7242bce67a9b0995cde3fe8a29c56a4d2fa453..3fc8e560284a0be1c8d9c3124f2874c91adbe199 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -3927,16 +3927,10 @@ void RenderFrameImpl::willSendRequest(
       request.setFirstPartyForCookies(frame->document().firstPartyForCookies());
   }
 
-  // Set the requestor origin to the same origin as the frame's document if it
-  // hasn't yet been set.
-  //
-  // TODO(mkwst): It would be cleaner to adjust blink::ResourceRequest to
-  // initialize itself with a `nullptr` initiator so that this can be a simple
-  // `isNull()` check.
-  if (request.requestorOrigin().isUnique() &&
-      !frame->document().getSecurityOrigin().isUnique()) {
-    request.setRequestorOrigin(frame->document().getSecurityOrigin());
-  }
+  // Unless we're navigating to a browser-generated error page, requests must
+  // have initiators.
+  DCHECK(!request.requestorOrigin().isNull() ||
+         request.url() == GURL(kUnreachableWebDataURL));
 
   WebDataSource* provisional_data_source = frame->provisionalDataSource();
   WebDataSource* data_source =