Add ServiceWorker.NavigationPreload.HeaderSize UMA

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"
 #include "base/feature_list.h"
 #include "base/memory/ptr_util.h"
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/browser/loader/resource_requester_info.h"
 #include "content/browser/loader/url_loader_factory_impl.h"
 #include "content/browser/service_worker/embedded_worker_status.h"
+#include "content/browser/service_worker/service_worker_metrics.h"
 #include "content/browser/service_worker/service_worker_version.h"
 #include "content/common/service_worker/service_worker_event_dispatcher.mojom.h"
 #include "content/common/service_worker/service_worker_messages.h"
 #include "content/common/service_worker/service_worker_status_code.h"
 #include "content/common/service_worker/service_worker_types.h"
 #include "content/common/service_worker/service_worker_utils.h"
 #include "content/public/common/browser_side_navigation_policy.h"
 #include "content/public/common/content_features.h"
 #include "mojo/public/cpp/bindings/associated_binding.h"
 #include "mojo/public/cpp/bindings/binding.h"
@@ skipping 409 matching lines @@
   // 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();
 
+  ServiceWorkerMetrics::RecordNavigationPreloadRequestHeaderSize(
+      version_->navigation_preload_state().header.length());

[falken, 2017/01/11 05:28:05]

nit: seems better to put this below line 452 or even line 455.

[horo, 2017/01/11 06:13:07]

Done.

   DCHECK(net::HttpUtil::IsValidHeaderValue(
       version_->navigation_preload_state().header));
   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;
@@ skipping 20 matching lines @@
 }
 
 ServiceWorkerMetrics::EventType ServiceWorkerFetchDispatcher::GetEventType()
     const {
   if (request_->fetch_type == ServiceWorkerFetchType::FOREIGN_FETCH)
     return ServiceWorkerMetrics::EventType::FOREIGN_FETCH;
   return ResourceTypeToEventType(resource_type_);
 }
 
 }  // namespace content