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

content/browser/loader/navigation_resource_handler.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/loader/navigation_resource_handler.h"
 
 #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_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/public/browser/resource_controller.h"
 #include "content/public/browser/stream_handle.h"
 #include "content/public/common/resource_response.h"
 #include "net/base/net_errors.h"
 #include "net/url_request/url_request.h"
 
 namespace content {
 
 NavigationResourceHandler::NavigationResourceHandler(
     net::URLRequest* request,
     NavigationURLLoaderImplCore* core)
     : ResourceHandler(request),
       core_(core) {
   core_->set_resource_handler(this);
-  writer_.set_immediate_mode(true);
+  // writer_.set_immediate_mode(true);
 }
 
 NavigationResourceHandler::~NavigationResourceHandler() {
   if (core_) {
     core_->NotifyRequestFailed(false, net::ERR_ABORTED);
     DetachFromCore();
   }
 }
 
 void NavigationResourceHandler::Cancel() {
@@ skipping 33 matching lines @@
   // If the MimeTypeResourceHandler intercepted this request and converted it
   // into a download, it will still call OnResponseStarted and immediately
   // cancel. Ignore the call; OnReadCompleted will happen shortly.
   //
   // TODO(davidben): Move the dispatch out of MimeTypeResourceHandler. Perhaps
   // all the way to the UI thread. Downloads, user certificates, etc., should be
   // dispatched at the navigation layer.
   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;
 }
 
 bool NavigationResourceHandler::OnWillStart(const GURL& url, bool* defer) {
   return true;
 }
 
 bool NavigationResourceHandler::OnBeforeNetworkStart(const GURL& url,
                                                      bool* defer) {
@@ skipping 13 matching lines @@
 }
 
 void NavigationResourceHandler::OnResponseCompleted(
     const net::URLRequestStatus& status,
     const std::string& security_info,
     bool* defer) {
   // If the request has already committed, close the stream and leave it as-is.
   //
   // 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;
   }
 
   if (core_) {
     DCHECK_NE(net::OK, status.error());
     core_->NotifyRequestFailed(request()->response_info().was_cached,
                                status.error());
     DetachFromCore();
   }
 }
 
 void NavigationResourceHandler::OnDataDownloaded(int bytes_downloaded) {
   NOTREACHED();
 }
 
 void NavigationResourceHandler::DetachFromCore() {
   DCHECK(core_);
   core_->set_resource_handler(nullptr);
   core_ = nullptr;
 }
 
 }  // namespace content