PlzNavigate: make NavigationResourceHandler a LayeredResourceHandler

content/browser/loader/resource_dispatcher_host_impl.cc

 // Copyright (c) 2012 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.
 
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
 
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 
 #include <stddef.h>
 
@@ skipping 506 matching lines @@
   GURL origin;
   if (!delegate_ ||
       !delegate_->ShouldInterceptResourceAsStream(
           request, plugin_path, mime_type, &origin, payload)) {
     return std::unique_ptr<ResourceHandler>();
   }
 
   StreamContext* stream_context =
       GetStreamContextForResourceContext(info->GetContext());
 
-  std::unique_ptr<StreamResourceHandler> handler(
-      new StreamResourceHandler(request, stream_context->registry(), origin));
+  std::unique_ptr<StreamResourceHandler> handler(new StreamResourceHandler(
+      request, stream_context->registry(), origin, false));
 
   info->set_is_stream(true);
   std::unique_ptr<StreamInfo> stream_info(new StreamInfo);
   stream_info->handle = handler->stream()->CreateHandle();
   stream_info->original_url = request->url();
   stream_info->mime_type = mime_type;
   // Make a copy of the response headers so it is safe to pass across threads;
   // the old handler (AsyncResourceHandler) may modify it in parallel via the
   // ResourceDispatcherHostDelegate.
   if (response->head.headers.get()) {
@@ skipping 931 matching lines @@
       IsResourceTypeFrame(request_data.resource_type)) {
     DCHECK(request->url().SchemeIs(url::kBlobScheme));
     return handler;
   }
 
   return AddStandardHandlers(request, request_data.resource_type,
                              resource_context,
                              request_data.fetch_request_context_type,
                              request_data.fetch_mixed_content_context_type,
                              requester_info->appcache_service(), child_id,
-                             route_id, std::move(handler));
+                             route_id, std::move(handler), nullptr, nullptr);
 }
 
 std::unique_ptr<ResourceHandler>
 ResourceDispatcherHostImpl::AddStandardHandlers(
     net::URLRequest* request,
     ResourceType resource_type,
     ResourceContext* resource_context,
     RequestContextType fetch_request_context_type,
     blink::WebMixedContentContextType fetch_mixed_content_context_type,
     AppCacheService* appcache_service,
     int child_id,
     int route_id,
-    std::unique_ptr<ResourceHandler> handler) {
+    std::unique_ptr<ResourceHandler> handler,
+    NavigationURLLoaderImplCore* navigation_loader_core,
+    std::unique_ptr<StreamHandle> stream_handle) {
   // The InterceptingResourceHandler will replace its next handler with an
   // appropriate one based on the MIME type of the response if needed. It
   // should be placed at the end of the chain, just before |handler|.
   handler.reset(new InterceptingResourceHandler(std::move(handler), request));
   InterceptingResourceHandler* intercepting_handler =
       static_cast<InterceptingResourceHandler*>(handler.get());
 
   std::vector<std::unique_ptr<ResourceThrottle>> throttles;
 
   // Add a NavigationResourceThrottle for navigations.
   // PlzNavigate: the throttle is unnecessary as communication with the UI
-  // thread is handled by the NavigationURLloader.
+  // thread is handled by the NavigationResourceHandler below.
   if (!IsBrowserSideNavigationEnabled() && IsResourceTypeFrame(resource_type)) {
     throttles.push_back(base::MakeUnique<NavigationResourceThrottle>(
         request, delegate_, fetch_request_context_type,
         fetch_mixed_content_context_type));
   }
 
   if (delegate_) {
     delegate_->RequestBeginning(request,
                                 resource_context,
                                 appcache_service,
@@ skipping 23 matching lines @@
     } else {
       post_mime_sniffing_throttles.push_back(std::move(throttle));
     }
   }
   throttles.clear();
 
   // Add the post mime sniffing throttles.
   handler.reset(new ThrottlingResourceHandler(
       std::move(handler), request, std::move(post_mime_sniffing_throttles)));
 
+  if (IsBrowserSideNavigationEnabled() && IsResourceTypeFrame(resource_type)) {
+    DCHECK(navigation_loader_core);
+    DCHECK(stream_handle);
+    // PlzNavigate
+    // Add a NavigationResourceHandler that will control the flow of navigation.
+    handler.reset(new NavigationResourceHandler(
+        request, std::move(handler), navigation_loader_core, delegate(),
+        std::move(stream_handle)));
+  } else {
+    DCHECK(!navigation_loader_core);
+    DCHECK(!stream_handle);
+  }
+
   PluginService* plugin_service = nullptr;
 #if BUILDFLAG(ENABLE_PLUGINS)
   plugin_service = PluginService::GetInstance();
 #endif
 
   // Insert a buffered event handler to sniff the mime type.
   // Note: all ResourceHandler following the MimeSniffingResourceHandler
   // should expect OnWillRead to be called *before* OnResponseStarted as
   // part of the mime sniffing process.
   handler.reset(new MimeSniffingResourceHandler(
@@ skipping 507 matching lines @@
       info.begin_params.request_context_type, frame_type,
       info.are_ancestors_secure, info.common_params.post_data,
       extra_info->GetWebContentsGetterForRequest());
 
   // Have the appcache associate its extra info with the request.
   if (appcache_handle_core) {
     AppCacheInterceptor::SetExtraRequestInfoForHost(
         new_request.get(), appcache_handle_core->host(), resource_type, false);
   }
 
+  StreamContext* stream_context =
+      GetStreamContextForResourceContext(resource_context);
+  // Note: the stream should be created with immediate mode set to true to
+  // ensure that data read will be flushed to the reader as soon as it's
+  // available. Otherwise, we risk delaying transmitting the body of the
+  // resource to the renderer, which will delay parsing accordingly.
   std::unique_ptr<ResourceHandler> handler(
-      new NavigationResourceHandler(new_request.get(), loader, delegate()));
+      new StreamResourceHandler(new_request.get(), stream_context->registry(),
+                                new_request->url().GetOrigin(), true));
+  std::unique_ptr<StreamHandle> stream_handle =
+      static_cast<StreamResourceHandler*>(handler.get())
+          ->stream()
+          ->CreateHandle();
 
   // TODO(davidben): Fix the dependency on child_id/route_id. Those are used
   // by the ResourceScheduler. currently it's a no-op.
   handler = AddStandardHandlers(
       new_request.get(), resource_type, resource_context,
       info.begin_params.request_context_type,
       info.begin_params.mixed_content_context_type,
       appcache_handle_core ? appcache_handle_core->GetAppCacheService()
                            : nullptr,
       -1,  // child_id
       -1,  // route_id
-      std::move(handler));
+      std::move(handler), loader, std::move(stream_handle));
 
   BeginRequestInternal(std::move(new_request), std::move(handler));
 }
 
 void ResourceDispatcherHostImpl::SetLoaderDelegate(
     LoaderDelegate* loader_delegate) {
   loader_delegate_ = loader_delegate;
 }
 
 void ResourceDispatcherHostImpl::OnRenderFrameDeleted(
@@ skipping 515 matching lines @@
                                  &throttles);
     if (!throttles.empty()) {
       handler.reset(new ThrottlingResourceHandler(std::move(handler), request,
                                                   std::move(throttles)));
     }
   }
   return handler;
 }
 
 }  // namespace content