Show service worker navigation preload requests in DevTools Network tab

content/browser/service_worker/service_worker_fetch_dispatcher.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/service_worker/service_worker_fetch_dispatcher.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 427 matching lines @@
   request.load_flags = original_request->load_flags();
   // Set to SUB_RESOURCE because we shouldn't trigger NavigationResourceThrottle
   // for the service worker navigation preload request.
   request.resource_type = RESOURCE_TYPE_SUB_RESOURCE;
   request.priority = original_request->priority();
   request.skip_service_worker = SkipServiceWorker::ALL;
   request.do_not_prompt_for_login = true;
   request.render_frame_id = original_info->GetRenderFrameID();
   request.is_main_frame = original_info->IsMainFrame();
   request.parent_is_main_frame = original_info->ParentIsMainFrame();
+  request.enable_load_timing = original_info->is_load_timing_enabled();
+  request.report_raw_headers = original_info->ShouldReportRawHeaders();
 
   DCHECK(net::HttpUtil::IsValidHeaderValue(
       version_->navigation_preload_state().header));
   ServiceWorkerMetrics::RecordNavigationPreloadRequestHeaderSize(
       version_->navigation_preload_state().header.length());
   request.headers = "Service-Worker-Navigation-Preload: " +
                     version_->navigation_preload_state().header;
 
   const int request_id = ResourceDispatcherHostImpl::Get()->MakeRequestID();
   DCHECK_LT(request_id, -1);
 
   preload_handle_ = mojom::FetchEventPreloadHandle::New();
   mojom::URLLoaderClientPtr url_loader_client_ptr;
   preload_handle_->url_loader_client_request =
       mojo::MakeRequest(&url_loader_client_ptr);
   auto url_loader_client = base::MakeUnique<DelegatingURLLoaderClient>(
       std::move(url_loader_client_ptr));
   mojom::URLLoaderClientAssociatedPtrInfo url_loader_client_associated_ptr_info;
   url_loader_client->Bind(&url_loader_client_associated_ptr_info,
                           url_loader_factory_.associated_group());
   mojom::URLLoaderAssociatedPtr url_loader_associated_ptr;
 
+  preload_handle_->sent_timestamp =
+      base::TimeTicks::Now().ToInternalValue() /
+      static_cast<double>(base::Time::kMicrosecondsPerSecond);

[falken, 2017/01/17 14:38:36]

Is this converting microseconds to seconds? ToIntervalValue() docu says "please
don't do arithmetic on this". Can we avoid that?

[horo, 2017/01/18 14:25:02]

Humm...I think there is no other way.
There is the same logic in Blink code.
https://chromium.googlesource.com/chromium/src/+/57f212f/third_party/WebKit/S...

+  preload_handle_->sent_wall_time = base::Time::Now().ToDoubleT();

[falken, 2017/01/17 14:38:36]

Could we use Mojo time types instead of these, and then convert whatever
DevTools needs on the renderer side? Seems a bit nicer and more clear why we're
doing the conversions if it's immediately where the conversion is needed.

[horo, 2017/01/18 14:25:02]

Done.

+
   url_loader_factory_->CreateLoaderAndStart(
       mojo::MakeRequest(&url_loader_associated_ptr,
                         url_loader_factory_.associated_group()),
       original_info->GetRouteID(), request_id, request,
       std::move(url_loader_client_associated_ptr_info));
 
   std::unique_ptr<DelegatingURLLoader> url_loader(
       new DelegatingURLLoader(std::move(url_loader_associated_ptr)));
   preload_handle_->url_loader = url_loader->CreateInterfacePtrAndBind();
   url_loader_ = std::move(url_loader);
   url_loader_client_ = std::move(url_loader_client);
 }
 
 ServiceWorkerMetrics::EventType ServiceWorkerFetchDispatcher::GetEventType()
     const {
   if (request_->fetch_type == ServiceWorkerFetchType::FOREIGN_FETCH)
     return ServiceWorkerMetrics::EventType::FOREIGN_FETCH;
   return ResourceTypeToEventType(resource_type_);
 }
 
 }  // namespace content