[page_load_metrics] Add a NavigationThrottle for richer abort metrics

chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer_unittest.cc

 // Copyright 2015 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/aborts_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"
 
 class AbortsPageLoadMetricsObserverTest
     : public page_load_metrics::PageLoadMetricsObserverTestHarness {
  protected:
   void RegisterObservers(page_load_metrics::PageLoadTracker* tracker) override {
     tracker->AddObserver(base::WrapUnique(new AbortsPageLoadMetricsObserver()));
   }
 
   void SimulateTimingWithoutPaint() {
     page_load_metrics::PageLoadTiming timing;
     timing.navigation_start = base::Time::FromDoubleT(1);
     SimulateTimingUpdate(timing);
   }
 };
 
-TEST_F(AbortsPageLoadMetricsObserverTest, UnknownNavigationBeforeCommit) {
+TEST_F(AbortsPageLoadMetricsObserverTest, NewNavigationBeforeCommit) {
   StartNavigation(GURL("https://www.google.com"));
   // Simulate the user performing another navigation before commit.
   NavigateAndCommit(GURL("https://www.example.com"));
   histogram_tester().ExpectTotalCount(
-      internal::kHistogramAbortUnknownNavigationBeforeCommit, 1);
+      internal::kHistogramAbortNewNavigationBeforeCommit, 1);
+}
+
+TEST_F(AbortsPageLoadMetricsObserverTest, ReloadBeforeCommit) {
+  StartNavigation(GURL("https://www.google.com"));
+  // Simulate the user performing another navigation before commit.
+  NavigateWithPageTransitionAndCommit(GURL("https://www.example.com"),
+                                      ui::PAGE_TRANSITION_RELOAD);
+  histogram_tester().ExpectTotalCount(
+      internal::kHistogramAbortReloadBeforeCommit, 1);
+}
+
+TEST_F(AbortsPageLoadMetricsObserverTest, ForwardBackBeforeCommit) {
+  StartNavigation(GURL("https://www.google.com"));
+  // Simulate the user performing another navigation before commit.
+  NavigateWithPageTransitionAndCommit(GURL("https://www.example.com"),
+                                      ui::PAGE_TRANSITION_FORWARD_BACK);
+  histogram_tester().ExpectTotalCount(
+      internal::kHistogramAbortForwardBackBeforeCommit, 1);
 }
 
 TEST_F(AbortsPageLoadMetricsObserverTest,
-       UnknownProvisionalNavigationBeforeCommit) {
+       NewProvisionalNavigationBeforeCommit) {
   StartNavigation(GURL("https://www.google.com"));
   StartNavigation(GURL("https://www.example.com"));
   histogram_tester().ExpectTotalCount(
-      internal::kHistogramAbortUnknownNavigationBeforeCommit, 1);
+      internal::kHistogramAbortNewNavigationBeforeCommit, 1);
 }
 
 TEST_F(AbortsPageLoadMetricsObserverTest,
-       UnknownNavigationBeforeCommitNonTrackedPageLoad) {
+       NewNavigationBeforeCommitNonTrackedPageLoad) {
   StartNavigation(GURL("https://www.google.com"));
   // Simulate the user performing another navigation before commit. Navigate to
   // an untracked URL, to verify that we still log abort metrics even if the new
   // navigation isn't tracked.
   NavigateAndCommit(GURL("about:blank"));
   histogram_tester().ExpectTotalCount(
-      internal::kHistogramAbortUnknownNavigationBeforeCommit, 1);
+      internal::kHistogramAbortNewNavigationBeforeCommit, 1);
 }
 
 TEST_F(AbortsPageLoadMetricsObserverTest, NewNavigationBeforePaint) {
   NavigateAndCommit(GURL("https://www.google.com"));
   SimulateTimingWithoutPaint();
   // Simulate the user performing another navigation before paint.
   NavigateAndCommit(GURL("https://www.example.com"));
   histogram_tester().ExpectTotalCount(
       internal::kHistogramAbortNewNavigationBeforePaint, 1);
   histogram_tester().ExpectTotalCount(
@@ skipping 152 matching lines @@
 
   NavigateAndCommit(GURL("https://www.example.com"));
 
   base::HistogramTester::CountsMap counts_map =
       histogram_tester().GetTotalCountsForPrefix(
           internal::kHistogramAbortNewNavigationBeforePaint);
 
   EXPECT_TRUE(counts_map.empty() ||
               (counts_map.size() == 1 && counts_map.begin()->second == 1));
 }