PROTOTYPE: PlzNavigate: use a Mojo data pipe to stream navigation data to the renderer.

content/browser/loader/navigation_resource_handler.cc

Index: content/browser/loader/navigation_resource_handler.cc
diff --git a/content/browser/loader/navigation_resource_handler.cc b/content/browser/loader/navigation_resource_handler.cc
index 94e046dbf0c74bf8044e6cd93484c3cab38563fa..c95e201439b5e6e506a88fccc154d256bf4a7113 100644
--- a/content/browser/loader/navigation_resource_handler.cc
+++ b/content/browser/loader/navigation_resource_handler.cc
@@ -25,7 +25,7 @@ NavigationResourceHandler::NavigationResourceHandler(
     : ResourceHandler(request),
       core_(core) {
   core_->set_resource_handler(this);
-  writer_.set_immediate_mode(true);
+  // writer_.set_immediate_mode(true);
 }
 
 NavigationResourceHandler::~NavigationResourceHandler() {
@@ -79,15 +79,15 @@ bool NavigationResourceHandler::OnResponseStarted(ResourceResponse* response,
   if (info->IsDownload() || info->is_stream())
     return true;
 
-  StreamContext* stream_context =
-      GetStreamContextForResourceContext(info->GetContext());
-  writer_.InitializeStream(stream_context->registry(),
-                           request()->url().GetOrigin());
+  mojo::ScopedDataPipeConsumerHandle data_consumer_handle;
+  writer_.InitializeStream(&data_consumer_handle);
 
   // Detach from the loader; at this point, the request is now owned by the
   // StreamHandle.
   DevToolsNetLogObserver::PopulateResponseInfo(request(), response);
-  core_->NotifyResponseStarted(response, writer_.stream()->CreateHandle());
+  // MAYBE SHOULD SEND THE CONSUMER HANDLE REFERENCE DIRECTLY FROM HERE?
+  core_->NotifyResponseStarted(
+    response, scoped_ptr<StreamHandle>(), std::move(data_consumer_handle));
   DetachFromCore();
   return true;
 }
@@ -121,7 +121,7 @@ void NavigationResourceHandler::OnResponseCompleted(
   //
   // TODO(davidben): The net error code should be passed through StreamWriter
   // down to the stream's consumer. See https://crbug.com/426162.
-  if (writer_.stream()) {
+  if (writer_.has_stream()) {
     writer_.Finalize();
     return;
   }