Added UkmPageLoadMetricsObserver which sends top-level metrics to UKM

chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer_unittest.cc

Index: chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer_unittest.cc
diff --git a/chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer_unittest.cc b/chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d289ab460e927b1b82df58f481642283a9681391
--- /dev/null
+++ b/chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer_unittest.cc
@@ -0,0 +1,74 @@
+// 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/ukm_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/test/base/testing_browser_process.h"
+#include "components/ukm/test_ukm_service.h"
+#include "components/ukm/ukm_source.h"
+
+namespace {
+
+const char kDefaultTestUrl[] = "https://google.com";
+
+}  // namespace
+
+class UkmPageLoadMetricsObserverTest
+    : public page_load_metrics::PageLoadMetricsObserverTestHarness {
+ protected:
+  void RegisterObservers(page_load_metrics::PageLoadTracker* tracker) override {
+    tracker->AddObserver(base::MakeUnique<UkmPageLoadMetricsObserver>());
+  }
+
+  void SetUp() override {
+    page_load_metrics::PageLoadMetricsObserverTestHarness::SetUp();
+
+    TestingBrowserProcess::GetGlobal()->SetUkmService(
+        ukm_service_test_harness_.test_ukm_service());
+  }
+
+  void InitializeTestPageLoadTiming(page_load_metrics::PageLoadTiming* timing) {
+    timing->navigation_start = base::Time::FromInternalValue(1);
+    timing->first_contentful_paint = base::TimeDelta::FromInternalValue(300);
+    PopulateRequiredTimingFields(timing);
+  }
+
+  size_t ukm_source_count() {
+    return ukm_service_test_harness_.test_ukm_service()->sources_count();
+  }
+
+  const ukm::UkmSource* GetUkmSource(size_t source_index) {
+    return ukm_service_test_harness_.test_ukm_service()->GetSource(
+        source_index);
+  }
+
+ private:
+  ukm::UkmServiceTestingHarness ukm_service_test_harness_;
+};
+
+TEST_F(UkmPageLoadMetricsObserverTest, NoMetrics) {
+  EXPECT_EQ(0ul, ukm_source_count());
+}
+
+TEST_F(UkmPageLoadMetricsObserverTest, FirstContentfulPaint) {
+  page_load_metrics::PageLoadTiming timing;
+  InitializeTestPageLoadTiming(&timing);
+
+  NavigateAndCommit(GURL(kDefaultTestUrl));
+  SimulateTimingUpdate(timing);
+
+  // Simulate closing the tab.
+  DeleteContents();
+
+  EXPECT_EQ(1ul, ukm_source_count());
+
+  const ukm::UkmSource* source = GetUkmSource(0);
+  ASSERT_TRUE(source);
+
+  EXPECT_EQ(GURL(kDefaultTestUrl), source->committed_url());
+  EXPECT_EQ(base::TimeDelta::FromInternalValue(300),
+            source->first_contentful_paint());
+}