predictors: Mark before_first_contentful_paint for resources fetched before fcp.

chrome/browser/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer_unittest.cc

 // Copyright 2017 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/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.h"
 
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.h"
 #include "chrome/browser/predictors/resource_prefetch_common.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor.h"
+#include "chrome/browser/sessions/session_tab_helper.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 using predictors::ResourcePrefetchPredictor;
 
 class MockResourcePrefetchPredictor : public ResourcePrefetchPredictor {
  public:
   MockResourcePrefetchPredictor(
       const predictors::ResourcePrefetchPredictorConfig& config,
@@ skipping 18 matching lines @@
     timing_.navigation_start = base::Time::FromDoubleT(1);
     timing_.paint_timing.first_paint = base::TimeDelta::FromSeconds(2);
     timing_.paint_timing.first_contentful_paint =
         base::TimeDelta::FromSeconds(3);
     timing_.paint_timing.first_meaningful_paint =
         base::TimeDelta::FromSeconds(4);
     PopulateRequiredTimingFields(&timing_);
   }
 
   void RegisterObservers(page_load_metrics::PageLoadTracker* tracker) override {
+    // SessionTabHelper::CreateForWebContents(web_contents());

[alexilin, 2017/04/21 13:49:05]

Do you still need this?

[trevordixon, 2017/04/25 12:46:09]

Nope.

[alexilin, 2017/04/25 18:42:21]

Nit: 
remove #include "chrome/browser/sessions/session_tab_helper.h" as it's unused.

     tracker->AddObserver(
         base::MakeUnique<ResourcePrefetchPredictorPageLoadMetricsObserver>(
-            predictor_.get()));
+            predictor_.get(), web_contents()));
   }
 
   std::unique_ptr<testing::StrictMock<MockResourcePrefetchPredictor>>
       predictor_;
   page_load_metrics::PageLoadTiming timing_;
 };
 
 TEST_F(ResourcePrefetchPredictorPageLoadMetricsObserverTest,
        PrefetchableIsRecorded) {
   const GURL main_frame_url("https://www.google.com");
@@ skipping 16 matching lines @@
       .WillOnce(testing::Return(false));
 
   NavigateAndCommit(main_frame_url);
   SimulateTimingUpdate(timing_);
 
   histogram_tester().ExpectTotalCount(
       internal::kHistogramResourcePrefetchPredictorFirstContentfulPaint, 0);
   histogram_tester().ExpectTotalCount(
       internal::kHistogramResourcePrefetchPredictorFirstMeaningfulPaint, 0);
 }