Adding DRP specfic UMA for FirstContentfulPaint

chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.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.
 
 #include "chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.h"
 
 #include <stdint.h>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 11 matching lines @@
 #include "chrome/browser/download/download_resource_throttle.h"
 #include "chrome/browser/mod_pagespeed/mod_pagespeed_metrics.h"
 #include "chrome/browser/net/resource_prefetch_predictor_observer.h"
 #include "chrome/browser/plugins/plugin_prefs.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/prerender/prerender_manager_factory.h"
 #include "chrome/browser/prerender/prerender_resource_throttle.h"
 #include "chrome/browser/prerender/prerender_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_io_data.h"
+#include "chrome/browser/renderer_host/chrome_navigation_data.h"
 #include "chrome/browser/renderer_host/safe_browsing_resource_throttle.h"
 #include "chrome/browser/renderer_host/thread_hop_resource_throttle.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
 #include "chrome/browser/signin/chrome_signin_helper.h"
 #include "chrome/browser/tab_contents/tab_util.h"
 #include "chrome/browser/ui/login/login_handler.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/features.h"
 #include "chrome/common/url_constants.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_data.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
 #include "components/google/core/browser/google_util.h"
 #include "components/policy/core/common/cloud/policy_header_io_helper.h"
 #include "components/variations/net/variations_http_headers.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/navigation_data.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/plugin_service.h"
 #include "content/public/browser/plugin_service_filter.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/resource_context.h"
 #include "content/public/browser/resource_dispatcher_host.h"
 #include "content/public/browser/resource_request_info.h"
 #include "content/public/browser/service_worker_context.h"
 #include "content/public/browser/stream_info.h"
@@ skipping 658 matching lines @@
     return data_reduction_proxy_io_data->ShouldEnableLoFiMode(url_request);
   return false;
 }
 
 // static
 void ChromeResourceDispatcherHostDelegate::
     SetExternalProtocolHandlerDelegateForTesting(
     ExternalProtocolHandler::Delegate* delegate) {
   g_external_protocol_handler_delegate = delegate;
 }
+
+content::NavigationData*
+ChromeResourceDispatcherHostDelegate::GetNavigationData(
+    net::URLRequest* request) const {
+  ChromeNavigationData* data =
+      ChromeNavigationData::GetDataAndCreateIfNecessary(request);
+  if (request) {
+    data_reduction_proxy::DataReductionProxyData* data_reduction_proxy_data =
+        data_reduction_proxy::DataReductionProxyData::GetData(*request);
+    // DeepCopy the DataReductionProxyData from the URLRequest to prevent the
+    // URLRequest and DataReductionProxyData from both having ownership of the
+    // same object. This copy will be shortlived as it will be deep copied again
+    // when content makes a clone of NavigationData for the UI thread.
+    if (data_reduction_proxy_data)
+      data->SetDataReductionProxyData(data_reduction_proxy_data->DeepCopy());

[mmenke, 2016/05/06 18:59:36]

This seems worse than the last iteration - we're reusing ChromeNavigationData,
but any time it's accessed, we overwrite its DataReductionProxyData.  I hadn't
realized you were intended to copy the DRP data here.

Oh well - I'll just defer to nasko on this one.

[RyanSturm, 2016/05/06 20:55:44]

This method wasn't intended to be called more than once. I see your concern.
Instead of DeepCopying, it can copy the state from one to the other if
ChromeNavigationData already has a DataReductionProxyData. I'm not sure if that
is the approach we want. If we expected this to get called a few times, and the
DeepCopy does become expensive, it might be.

If SupportsUserData used ref counting instead of unique_ptr, we could just keep
the DataReductionProxyData in sync through that mechanism, but without the ref
counting it just isn't feasible.

Perhaps for clarity, this method should be renamed, CreateNavigationData, but
that also doesn't necessarily seem like the best approach due to the fact that
it might not create a new one. MaybeCreateNavigationDataForURLRequest? I'm
really not sure what the best approach is.

+  }
+  return data;
+}