Add a UKM observer to measure time spent in foreground.

The observer uses a repeated field because a tab or window can be
backgrounded and foregrounded multiple times.

Bug: 921703
Change-Id: If03a3444a237d7c5abf0740a0a3c9c684caea013
Reviewed-on: https://chromium-review.googlesource.com/c/1421681Reviewed-by: Bryan McQuade <bmcquade@chromium.org>
Commit-Queue: Annie Sullivan <sullivan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#626232}

chrome/browser/BUILD.gn

@@ -956,6 +956,8 @@ jumbo_split_static_library("browser") {
     "page_load_metrics/observers/data_use_metrics_observer.h",
     "page_load_metrics/observers/document_write_page_load_metrics_observer.cc",
     "page_load_metrics/observers/document_write_page_load_metrics_observer.h",
+    "page_load_metrics/observers/foreground_duration_ukm_observer.cc",
+    "page_load_metrics/observers/foreground_duration_ukm_observer.h",
     "page_load_metrics/observers/from_gws_page_load_metrics_observer.cc",
     "page_load_metrics/observers/from_gws_page_load_metrics_observer.h",
     "page_load_metrics/observers/histogram_suffixes.cc",

chrome/browser/page_load_metrics/observers/foreground_duration_ukm_observer.cc

+// Copyright 2019 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/foreground_duration_ukm_observer.h"
+
+#include "base/time/time.h"
+#include "chrome/browser/page_load_metrics/page_load_metrics_observer.h"
+#include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
+#include "chrome/common/page_load_metrics/page_load_timing.h"
+#include "content/public/browser/navigation_handle.h"
+#include "services/metrics/public/cpp/ukm_builders.h"
+#include "services/metrics/public/cpp/ukm_recorder.h"
+#include "services/metrics/public/cpp/ukm_source.h"
+
+ForegroundDurationUKMObserver::ForegroundDurationUKMObserver() {}
+
+ForegroundDurationUKMObserver::~ForegroundDurationUKMObserver() {}
+
+page_load_metrics::PageLoadMetricsObserver::ObservePolicy
+ForegroundDurationUKMObserver::OnStart(
+    content::NavigationHandle* navigation_handle,
+    const GURL& currently_committed_url,
+    bool started_in_foreground) {
+  currently_in_foreground_ = started_in_foreground;
+  if (currently_in_foreground_) {
+    last_time_shown_ = navigation_handle->NavigationStart();
+  }
+  return CONTINUE_OBSERVING;
+}
+
+page_load_metrics::PageLoadMetricsObserver::ObservePolicy
+ForegroundDurationUKMObserver::OnCommit(
+    content::NavigationHandle* navigation_handle,
+    ukm::SourceId source_id) {
+  source_id_ = source_id;
+  return CONTINUE_OBSERVING;
+}
+
+page_load_metrics::PageLoadMetricsObserver::ObservePolicy
+ForegroundDurationUKMObserver::FlushMetricsOnAppEnterBackground(
+    const page_load_metrics::mojom::PageLoadTiming& timing,
+    const page_load_metrics::PageLoadExtraInfo& info) {
+  RecordUkmIfInForeground();
+  return CONTINUE_OBSERVING;
+}
+
+page_load_metrics::PageLoadMetricsObserver::ObservePolicy
+ForegroundDurationUKMObserver::OnHidden(
+    const page_load_metrics::mojom::PageLoadTiming& timing,
+    const page_load_metrics::PageLoadExtraInfo& info) {
+  RecordUkmIfInForeground();
+  return CONTINUE_OBSERVING;
+}
+page_load_metrics::PageLoadMetricsObserver::ObservePolicy
+ForegroundDurationUKMObserver::OnShown() {
+  if (!currently_in_foreground_) {
+    last_time_shown_ = base::TimeTicks::Now();
+    currently_in_foreground_ = true;
+  }
+  return CONTINUE_OBSERVING;
+}
+
+void ForegroundDurationUKMObserver::OnComplete(
+    const page_load_metrics::mojom::PageLoadTiming& timing,
+    const page_load_metrics::PageLoadExtraInfo& info) {
+  RecordUkmIfInForeground();
+}
+
+void ForegroundDurationUKMObserver::RecordUkmIfInForeground() {
+  if (!currently_in_foreground_)
+    return;
+  base::TimeDelta foreground_duration =
+      base::TimeTicks::Now() - last_time_shown_;
+  ukm::UkmRecorder* ukm_recorder = ukm::UkmRecorder::Get();
+  ukm::builders::PageForegroundSession(source_id_)
+      .SetForegroundDuration(foreground_duration.InMilliseconds())
+      .Record(ukm_recorder);
+  currently_in_foreground_ = false;
+}

chrome/browser/page_load_metrics/observers/foreground_duration_ukm_observer.h

+// Copyright 2019 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.
+
+#ifndef CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_FOREGROUND_DURATION_UKM_OBSERVER_H_
+#define CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_FOREGROUND_DURATION_UKM_OBSERVER_H_
+
+#include "base/time/time.h"
+#include "chrome/browser/page_load_metrics/page_load_metrics_observer.h"
+#include "services/metrics/public/cpp/ukm_source_id.h"
+
+// Observer responsible for appending previews information to the PLM UKM
+// report.
+class ForegroundDurationUKMObserver
+    : public page_load_metrics::PageLoadMetricsObserver {
+ public:
+  ForegroundDurationUKMObserver();
+  ~ForegroundDurationUKMObserver() override;
+
+  // page_load_metrics::PageLoadMetricsObserver:
+  ObservePolicy OnStart(content::NavigationHandle* navigation_handle,
+                        const GURL& currently_committed_url,
+                        bool started_in_foreground) override;
+  ObservePolicy OnCommit(content::NavigationHandle* navigation_handle,
+                         ukm::SourceId source_id) override;
+  ObservePolicy FlushMetricsOnAppEnterBackground(
+      const page_load_metrics::mojom::PageLoadTiming& timing,
+      const page_load_metrics::PageLoadExtraInfo& info) override;
+  ObservePolicy OnHidden(
+      const page_load_metrics::mojom::PageLoadTiming& timing,
+      const page_load_metrics::PageLoadExtraInfo& info) override;
+  ObservePolicy OnShown() override;
+  void OnComplete(const page_load_metrics::mojom::PageLoadTiming& timing,
+                  const page_load_metrics::PageLoadExtraInfo& info) override;
+
+ private:
+  bool currently_in_foreground_ = false;
+  base::TimeTicks last_time_shown_;
+  ukm::SourceId source_id_ = ukm::kInvalidSourceId;
+  void RecordUkmIfInForeground();
+
+  DISALLOW_COPY_AND_ASSIGN(ForegroundDurationUKMObserver);
+};
+
+#endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_FOREGROUND_DURATION_UKM_OBSERVER_H_

chrome/browser/page_load_metrics/observers/foreground_duration_ukm_observer_browsertest.cc

+// Copyright 2019 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/foreground_duration_ukm_observer.h"
+
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_commands.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/common/webui_url_constants.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "components/ukm/test_ukm_recorder.h"
+#include "content/public/test/browser_test_utils.h"
+#include "content/public/test/test_utils.h"
+#include "net/test/embedded_test_server/embedded_test_server.h"
+#include "services/metrics/public/cpp/ukm_builders.h"
+#include "services/metrics/public/cpp/ukm_source.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/base/window_open_disposition.h"
+#include "url/gurl.h"
+
+using UkmEntry = ukm::builders::PageForegroundSession;
+
+class ForegroundDurationUKMObserverBrowserTest : public InProcessBrowserTest {
+ public:
+  ForegroundDurationUKMObserverBrowserTest() {}
+  ~ForegroundDurationUKMObserverBrowserTest() override {}
+
+  void PreRunTestOnMainThread() override {
+    InProcessBrowserTest::PreRunTestOnMainThread();
+    test_ukm_recorder_ = std::make_unique<ukm::TestAutoSetUkmRecorder>();
+  }
+
+ protected:
+  void StartHttpsServer(net::EmbeddedTestServer::ServerCertificate cert) {
+    https_test_server_ = std::make_unique<net::EmbeddedTestServer>(
+        net::EmbeddedTestServer::TYPE_HTTPS);
+    https_test_server_->SetSSLConfig(cert);
+    https_test_server_->ServeFilesFromSourceDirectory("chrome/test/data");
+    ASSERT_TRUE(https_test_server_->Start());
+  }
+  void ExpectMetricCountForUrl(const GURL& url,
+                               const char* metric_name,
+                               const int expected_count) {
+    int count = 0;
+    for (auto* entry :
+         test_ukm_recorder_->GetEntriesByName(UkmEntry::kEntryName)) {
+      auto* source = test_ukm_recorder_->GetSourceForSourceId(entry->source_id);
+      if (source && source->url() == url) {
+        test_ukm_recorder_->EntryHasMetric(entry, metric_name);
+        count++;
+      }
+    }
+    EXPECT_EQ(count, expected_count);
+  }
+
+  void CloseAllTabs() {
+    TabStripModel* tab_strip_model = browser()->tab_strip_model();
+    content::WebContentsDestroyedWatcher destroyed_watcher(
+        tab_strip_model->GetActiveWebContents());
+    tab_strip_model->CloseAllTabs();
+    destroyed_watcher.Wait();
+  }
+
+  net::EmbeddedTestServer* https_test_server() {
+    return https_test_server_.get();
+  }
+
+ private:
+  std::unique_ptr<ukm::TestAutoSetUkmRecorder> test_ukm_recorder_;
+  std::unique_ptr<net::EmbeddedTestServer> https_test_server_;
+
+  DISALLOW_COPY_AND_ASSIGN(ForegroundDurationUKMObserverBrowserTest);
+};
+
+IN_PROC_BROWSER_TEST_F(ForegroundDurationUKMObserverBrowserTest, RecordSimple) {
+  StartHttpsServer(net::EmbeddedTestServer::CERT_OK);
+  GURL url = https_test_server()->GetURL("/simple.html");
+  ui_test_utils::NavigateToURL(browser(), url);
+  CloseAllTabs();
+  ExpectMetricCountForUrl(url, "ForegroundDuration", 1);
+}
+
+IN_PROC_BROWSER_TEST_F(ForegroundDurationUKMObserverBrowserTest, TabSwitching) {
+  StartHttpsServer(net::EmbeddedTestServer::CERT_OK);
+  GURL url1 = https_test_server()->GetURL("/simple.html");
+  GURL url2 = https_test_server()->GetURL("/form.html");
+  ui_test_utils::NavigateToURL(browser(), url1);
+  ui_test_utils::NavigateToURLWithDisposition(
+      browser(), url2, WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+
+  TabStripModel* tab_strip_model = browser()->tab_strip_model();
+  EXPECT_EQ(2, tab_strip_model->count());
+  EXPECT_EQ(url1, tab_strip_model->GetWebContentsAt(0)->GetURL());
+  EXPECT_EQ(url2, tab_strip_model->GetWebContentsAt(1)->GetURL());
+
+  tab_strip_model->ActivateTabAt(0, true);
+  tab_strip_model->ActivateTabAt(1, true);
+  tab_strip_model->ActivateTabAt(0, true);
+  tab_strip_model->ActivateTabAt(1, true);
+  tab_strip_model->CloseAllTabs();
+  ExpectMetricCountForUrl(url1, "ForegroundDuration", 3);
+  ExpectMetricCountForUrl(url2, "ForegroundDuration", 3);
+}

chrome/browser/page_load_metrics/page_load_metrics_initialize.cc

@@ -19,6 +19,7 @@
 #include "chrome/browser/page_load_metrics/observers/data_saver_site_breakdown_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/data_use_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/document_write_page_load_metrics_observer.h"
+#include "chrome/browser/page_load_metrics/observers/foreground_duration_ukm_observer.h"
 #include "chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/https_engagement_metrics/https_engagement_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/live_tab_count_page_load_metrics_observer.h"
@@ -100,6 +101,7 @@ void PageLoadMetricsEmbedder::RegisterObservers(
     tracker->AddObserver(
         std::make_unique<data_reduction_proxy::LoFiPageLoadMetricsObserver>());
     tracker->AddObserver(std::make_unique<FromGWSPageLoadMetricsObserver>());
+    tracker->AddObserver(std::make_unique<ForegroundDurationUKMObserver>());
     tracker->AddObserver(
         std::make_unique<DocumentWritePageLoadMetricsObserver>());
     tracker->AddObserver(

chrome/test/BUILD.gn

@@ -727,6 +727,7 @@ test("browser_tests") {
       "../browser/page_load_metrics/observers/ads_page_load_metrics_observer_browsertest.cc",
       "../browser/page_load_metrics/observers/data_saver_site_breakdown_metrics_observer_browsertest.cc",
       "../browser/page_load_metrics/observers/data_use_metrics_observer_browsertest.cc",
+      "../browser/page_load_metrics/observers/foreground_duration_ukm_observer_browsertest.cc",
       "../browser/page_load_metrics/observers/https_engagement_metrics/https_engagement_page_load_metrics_observer_browsertest.cc",
       "../browser/page_load_metrics/observers/live_tab_count_page_load_metrics_observer_browsertest.cc",
       "../browser/page_load_metrics/observers/multi_tab_loading_page_load_metrics_observer_browsertest.cc",

tools/metrics/ukm/ukm.xml

@@ -1711,6 +1711,20 @@ be describing additional metrics about the same event.
   </metric>
 </event>
 
+<event name="PageForegroundSession">
+  <owner>sullivan@chromium.org</owner>
+  <summary>
+    Total time in foreground in milliseconds, recorded each time the page is
+    backgrounded. May be recorded multiple times for a single page visit.
+  </summary>
+  <metric name="ForegroundDuration">
+    <summary>
+      Total time in foreground in milliseconds, recorded each time the page is
+      backgrounded.
+    </summary>
+  </metric>
+</event>
+
 <event name="Intervention.DocumentWrite.ScriptBlock" singular="True">
   <owner>bmcquade@chromium.org</owner>
   <summary>