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..74373c87c8346030f049d97f7b985b7e1ff8cdfe 100644
--- a/content/browser/loader/navigation_resource_handler.cc
+++ b/content/browser/loader/navigation_resource_handler.cc
@@ -7,10 +7,12 @@
 #include "base/logging.h"
 #include "content/browser/devtools/devtools_netlog_observer.h"
 #include "content/browser/loader/navigation_url_loader_impl_core.h"
+#include "content/browser/loader/resource_message_filter.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/browser/resource_context_impl.h"
 #include "content/browser/streams/stream.h"
 #include "content/browser/streams/stream_context.h"
+#include "content/common/resource_messages.h"
 #include "content/public/browser/resource_controller.h"
 #include "content/public/browser/stream_handle.h"
 #include "content/public/common/resource_response.h"
@@ -25,7 +27,6 @@ NavigationResourceHandler::NavigationResourceHandler(
     : ResourceHandler(request),
       core_(core) {
   core_->set_resource_handler(this);
-  writer_.set_immediate_mode(true);
 }
 
 NavigationResourceHandler::~NavigationResourceHandler() {
@@ -60,14 +61,37 @@ bool NavigationResourceHandler::OnRequestRedirected(
   DevToolsNetLogObserver::PopulateResponseInfo(request(), response);
   core_->NotifyRequestRedirected(redirect_info, response);
   *defer = true;
+
   return true;
 }
 
 bool NavigationResourceHandler::OnResponseStarted(ResourceResponse* response,
                                                   bool* defer) {
+  // TODO(carlosk): review the TODO below. :) When I wrote it I thought we
+  // needed to send ResourceMsg_ReceivedResponse from here but it seems we
+  // don't.
+  // TODO(carlosk): More "work" is done in
+  // AsyncResourceHandler::OnResponseStarted than here. Now that this is the
+  // resource handler actually carrying out the navigation load, some of that
+  // has to be done here to. I'm adding TODOs below for some that but I'm not
+  // fully sure of what's needed and what's not and further investigation is
+  // need.
+  // I'm assuming anything mentioning "upload", RDH delegate (we don't have one
+  // in this class), "download", InliningHelper (I don't think we need one) are
+  // not needed here.
+  // TODO(carlosk): The same as above should affect other methods existing in
+  // both classes.
   DCHECK(core_);
 
+  // TODO(carlosk): see if we need the time recording in
+  // response_started_ticks_ used later for UMA metrics.
+
   ResourceRequestInfoImpl* info = GetRequestInfo();
+  LOG(ERROR)
+      << "*** NavigationResourceHandler::OnResponseStarted frame_tree_node_id: "
+      << info->frame_tree_node_id();
+
+  // TODO(carlosk): see if we need the filter check.
 
   // If the MimeTypeResourceHandler intercepted this request and converted it
   // into a download, it will still call OnResponseStarted and immediately
@@ -79,16 +103,27 @@ 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, std::move(data_consumer_handle),
+                               GetRequestID());
   DetachFromCore();
+
+  // TODO(carlosk): see if we need the zoom level control here (I assume we do).
+
+  response->head.request_start = request()->creation_time();
+  response->head.response_start = base::TimeTicks::Now();
+
+  // TODO(carlosk): see if we need the guard for http://crbug.com/124680 using
+  // sent_received_response_msg_.
+
+  // TODO(carlosk): see if we need to send ResourceMsg_ReceivedCachedMetadata.
+
   return true;
 }
 
@@ -121,8 +156,12 @@ 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();
+    ResourceRequestInfoImpl* info = GetRequestInfo();
+    LOG(ERROR) << "*** NavigationResourceHandler::OnResponseCompleted "
+                  "frame_tree_node_id: "
+               << info->frame_tree_node_id();
     return;
   }