Add metrics for home button and back button

This CL adds user actions for pressing the home button and the back
button.

Bug: 1018916
Change-Id: I0d97812cbe53a0334dff7c32bbe016bd82d41c8e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1900389Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Andrew Xu <andrewxu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713570}

ash/shelf/back_button.cc

@@ -8,6 +8,8 @@
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_focus_cycler.h"
 #include "ash/strings/grit/ash_strings.h"
+#include "base/metrics/user_metrics.h"
+#include "base/metrics/user_metrics_action.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -57,6 +59,8 @@ void BackButton::OnShelfButtonAboutToRequestFocusFromTabTraversal(
 void BackButton::ButtonPressed(views::Button* sender,
                                const ui::Event& event,
                                views::InkDrop* ink_drop) {
+  base::RecordAction(base::UserMetricsAction("AppList_BackButtonPressed"));
+
   // Send up event as well as down event as ARC++ clients expect this sequence.
   // TODO: Investigate if we should be using the current modifiers.
   aura::Window* root_window = GetWidget()->GetNativeWindow()->GetRootWindow();

ash/shelf/home_button.cc

@@ -14,6 +14,8 @@
 #include "ash/shell.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
 #include "base/logging.h"
+#include "base/metrics/user_metrics.h"
+#include "base/metrics/user_metrics_action.h"
 #include "chromeos/strings/grit/chromeos_strings.h"
 #include "ui/aura/window.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -85,8 +87,14 @@ void HomeButton::OnShelfButtonAboutToRequestFocusFromTabTraversal(
 void HomeButton::ButtonPressed(views::Button* sender,
                                const ui::Event& event,
                                views::InkDrop* ink_drop) {
-  Shell::Get()->metrics()->RecordUserMetricsAction(
-      UMA_LAUNCHER_CLICK_ON_APPLIST_BUTTON);
+  if (Shell::Get()->tablet_mode_controller()->InTabletMode()) {
+    base::RecordAction(
+        base::UserMetricsAction("AppList_HomeButtonPressedTablet"));
+  } else {
+    base::RecordAction(
+        base::UserMetricsAction("AppList_HomeButtonPressedClamshell"));
+  }
+
   const AppListShowSource show_source =
       event.IsShiftDown() ? kShelfButtonFullscreen : kShelfButton;
   OnPressed(show_source, event.time_stamp());

ash/shelf/shelf_view_unittest.cc

@@ -1440,6 +1440,45 @@ TEST_F(ShelfViewTest, ShelfAlignmentClosesTooltip) {
   EXPECT_FALSE(tooltip_manager->IsVisible());
 }
 
+// Verifies that the time of button press is recorded correctly in clamshell.
+TEST_F(ShelfViewTest, HomeButtonMetricsInClamshell) {
+  const HomeButton* home_button = shelf_view_->shelf_widget()->GetHomeButton();
+
+  // Make sure we're not showing the app list.
+  EXPECT_FALSE(home_button->IsShowingAppList());
+
+  base::UserActionTester user_action_tester;
+  ASSERT_EQ(0, user_action_tester.GetActionCount(
+                   "AppList_HomeButtonPressedClamshell"));
+
+  GetEventGenerator()->GestureTapAt(
+      home_button->GetBoundsInScreen().CenterPoint());
+  ASSERT_EQ(1, user_action_tester.GetActionCount(
+                   "AppList_HomeButtonPressedClamshell"));
+  EXPECT_TRUE(home_button->IsShowingAppList());
+}
+
+// Verifies that the time of button press is recorded correctly in tablet.
+TEST_F(ShelfViewTest, HomeButtonMetricsInTablet) {
+  Shell::Get()->tablet_mode_controller()->SetEnabledForTest(true);
+  const HomeButton* home_button = shelf_view_->shelf_widget()->GetHomeButton();
+
+  // Make sure we're not showing the app list.
+  std::unique_ptr<aura::Window> window = CreateTestWindow();
+  wm::ActivateWindow(window.get());
+  EXPECT_FALSE(home_button->IsShowingAppList());
+
+  base::UserActionTester user_action_tester;
+  ASSERT_EQ(
+      0, user_action_tester.GetActionCount("AppList_HomeButtonPressedTablet"));
+
+  GetEventGenerator()->GestureTapAt(
+      home_button->GetBoundsInScreen().CenterPoint());
+  ASSERT_EQ(
+      1, user_action_tester.GetActionCount("AppList_HomeButtonPressedTablet"));
+  EXPECT_TRUE(home_button->IsShowingAppList());
+}
+
 class HotseatShelfViewTest : public ShelfViewTest,
                              public testing::WithParamInterface<bool> {
  public:

tools/metrics/actions/actions.xml

@@ -2360,6 +2360,11 @@ should be able to be added at any place in this file.
   <description>Please enter the description of this user action.</description>
 </action>
 
+<action name="AppList_BackButtonPressed">
+  <owner>andrewxu@chromium.org</owner>
+  <description>User pressed the back button.</description>
+</action>
+
 <action name="AppList_ClickOnApp">
   <owner>vadimt@chromium.org</owner>
   <description>
@@ -2403,6 +2408,16 @@ should be able to be added at any place in this file.
   <description>CrOS Launcher went from full to peeking state.</description>
 </action>
 
+<action name="AppList_HomeButtonPressedClamshell">
+  <owner>andrewxu@chromium.org</owner>
+  <description>User pressed the launcher button in clamshell.</description>
+</action>
+
+<action name="AppList_HomeButtonPressedTablet">
+  <owner>andrewxu@chromium.org</owner>
+  <description>User pressed the launcher button in tablet.</description>
+</action>
+
 <action name="AppList_HomeLauncherToMRUWindow">
   <owner>newcomer@chromium.org</owner>
   <owner>sammiequon@chromium.org</owner>