Read later: add metric recording how long the reading list is open.

Bug: 1163938
Change-Id: I383d348d0e08aa42c4aabbfab38c3e8c7ad19331
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2622274Reviewed-by: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Connie Wan <connily@chromium.org>
Commit-Queue: Caroline Rising <corising@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843509}

chrome/browser/ui/views/read_later/read_later_button.cc

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/ui/views/read_later/read_later_button.h"
 
+#include "base/bind.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/metrics/user_metrics.h"
 #include "base/metrics/user_metrics_action.h"
@@ -84,7 +85,11 @@ ReadLaterButton::ReadLaterButton(Browser* browser)
           IDS_READ_LATER_TITLE,
           this,
           browser->profile(),
-          GURL(chrome::kChromeUIReadLaterURL))) {
+          GURL(chrome::kChromeUIReadLaterURL))),
+      widget_open_timer_(base::BindRepeating([](base::TimeDelta time_elapsed) {
+        base::UmaHistogramMediumTimes("ReadingList.WindowDisplayedDuration",
+                                      time_elapsed);
+      })) {
   SetImageLabelSpacing(ChromeLayoutProvider::Get()->GetDistanceMetric(
       DISTANCE_RELATED_LABEL_HORIZONTAL_LIST));
 
@@ -143,6 +148,13 @@ void ReadLaterButton::OnThemeChanged() {
   LabelButton::OnThemeChanged();
 }
 
+void ReadLaterButton::OnWidgetDestroying(views::Widget* widget) {
+  DCHECK_EQ(webui_bubble_manager_->GetBubbleWidget(), widget);
+  DCHECK(bubble_widget_observation_.IsObservingSource(
+      webui_bubble_manager_->GetBubbleWidget()));
+  bubble_widget_observation_.Reset();
+}
+
 void ReadLaterButton::ButtonPressed() {
   BrowserView* const browser_view =
       BrowserView::GetBrowserViewForBrowser(browser_);
@@ -171,6 +183,12 @@ void ReadLaterButton::ButtonPressed() {
           base::UserMetricsAction("DesktopReadingList.OpenReadingList"));
       RecordBookmarkBarState(browser_);
       webui_bubble_manager_->ShowBubble();
+      // There should only ever be a single bubble widget active for the
+      // ReadLaterButton.
+      DCHECK(!bubble_widget_observation_.IsObserving());
+      bubble_widget_observation_.Observe(
+          webui_bubble_manager_->GetBubbleWidget());
+      widget_open_timer_.Reset(webui_bubble_manager_->GetBubbleWidget());
     }
   }
 }

chrome/browser/ui/views/read_later/read_later_button.h

@@ -8,6 +8,8 @@
 #include "chrome/browser/ui/views/bubble/webui_bubble_manager.h"
 #include "chrome/browser/ui/webui/read_later/read_later_ui.h"
 #include "ui/views/controls/button/label_button.h"
+#include "ui/views/widget/widget_observer.h"
+#include "ui/views/widget/widget_utils.h"
 
 class Browser;
 class WebUIBubbleDialogView;
@@ -15,7 +17,8 @@ class WebUIBubbleDialogView;
 // Button in the bookmarks bar that provides access to the corresponding
 // read later menu.
 // TODO(corising): Handle the the async presentation of the UI bubble.
-class ReadLaterButton : public views::LabelButton {
+class ReadLaterButton : public views::LabelButton,
+                        public views::WidgetObserver {
  public:
   explicit ReadLaterButton(Browser* browser);
   ReadLaterButton(const ReadLaterButton&) = delete;
@@ -34,6 +37,9 @@ class ReadLaterButton : public views::LabelButton {
   SkColor GetInkDropBaseColor() const override;
   void OnThemeChanged() override;
 
+  // views::WidgetObserver:
+  void OnWidgetDestroying(views::Widget* widget) override;
+
   void ButtonPressed();
 
   Browser* const browser_;
@@ -42,6 +48,11 @@ class ReadLaterButton : public views::LabelButton {
   WebUIBubbleDialogView* read_later_side_panel_bubble_ = nullptr;
 
   std::unique_ptr<WebUIBubbleManager<ReadLaterUI>> webui_bubble_manager_;
+
+  views::WidgetOpenTimer widget_open_timer_;
+
+  base::ScopedObservation<views::Widget, views::WidgetObserver>
+      bubble_widget_observation_{this};
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_READ_LATER_READ_LATER_BUTTON_H_

tools/metrics/histograms/histograms_xml/others/histograms.xml

@@ -12690,6 +12690,18 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
+<histogram name="ReadingList.WindowDisplayedDuration" units="ms"
+    expires_after="M92">
+  <owner>corising@chromium.org</owner>
+  <owner>chrome-desktop-ui-sea@google.com</owner>
+  <summary>
+    Records the amount of time between when a reading list bubble is opened and
+    when it is closed. It does so by recording the difference in time between
+    when the the hosting WebUIBubbleDialogView's Widget is first created and
+    when the widget is destroyed. This is logged on Desktop only.
+  </summary>
+</histogram>
+
 <histogram name="RecoveryComponent.Event" enum="RecoveryComponentEvent"
     expires_after="M77">
   <owner>robertshield@chromium.org</owner>