Added the Ash.Tab.TimeBetweenSwitchToExistingTabUserActions histogram…

… to track time between tab switches.

TEST=Manually verified histogram data added on ChromeOS.

BUG=478930

Review URL: https://codereview.chromium.org/1124153007

Cr-Commit-Position: refs/heads/master@{#330217}

ash/metrics/task_switch_metrics_recorder.cc

@@ -13,6 +13,9 @@ namespace {
 const char kShelfHistogramName[] =
     "Ash.Shelf.TimeBetweenNavigateToTaskSwitches";
 
+const char kTabStripHistogramName[] =
+    "Ash.Tab.TimeBetweenSwitchToExistingTabUserActions";
+
 const char kAcceleratorWindowCycleHistogramName[] =
     "Ash.WindowCycleController.TimeBetweenTaskSwitches";
 
@@ -22,6 +25,8 @@ const char* GetHistogramName(
   switch (task_switch_source) {
     case TaskSwitchMetricsRecorder::kShelf:
       return kShelfHistogramName;
+    case TaskSwitchMetricsRecorder::kTabStrip:
+      return kTabStripHistogramName;
     case TaskSwitchMetricsRecorder::kWindowCycleController:
       return kAcceleratorWindowCycleHistogramName;
   }

ash/metrics/task_switch_metrics_recorder.h

@@ -24,6 +24,8 @@ class ASH_EXPORT TaskSwitchMetricsRecorder {
   enum TaskSwitchSource {
     // All task switches caused by shelf buttons, not including sub-menus.
     kShelf,
+    // All task switches caused by the tab strip.
+    kTabStrip,
     // Task switches caused by the WindowCycleController (ie Alt+Tab).
     kWindowCycleController
   };

ash/metrics/task_switch_metrics_recorder_unittest.cc

@@ -92,4 +92,19 @@ TEST_F(TaskSwitchMetricsRecorderTest,
   histogram_tester_->ExpectTotalCount(kHistogramName, 2);
 }
 
+// Verifies that the TaskSwitchMetricsRecorder::kTabStrip source adds data to
+// the Ash.Tab.TimeBetweenSwitchToExistingTabUserActions histogram.
+TEST_F(TaskSwitchMetricsRecorderTest,
+       VerifyTaskSwitchesFromTheTabStripAreRecorded) {
+  const std::string kHistogramName =
+      "Ash.Tab.TimeBetweenSwitchToExistingTabUserActions";
+
+  OnTaskSwitch(TaskSwitchMetricsRecorder::kTabStrip);
+  OnTaskSwitch(TaskSwitchMetricsRecorder::kTabStrip);
+  histogram_tester_->ExpectTotalCount(kHistogramName, 1);
+
+  OnTaskSwitch(TaskSwitchMetricsRecorder::kTabStrip);
+  histogram_tester_->ExpectTotalCount(kHistogramName, 2);
+}
+
 }  // namespace ash

chrome/browser/ui/ash/chrome_shell_delegate.h

@@ -13,6 +13,7 @@
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
+#include "chrome/browser/ui/ash/metrics/chrome_user_metrics_recorder.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
@@ -93,6 +94,9 @@ class ChromeShellDelegate : public ash::ShellDelegate,
 
   ObserverList<ash::VirtualKeyboardStateObserver> keyboard_state_observer_list_;
 
+  // Proxies events from chrome/browser to ash::UserMetricsRecorder.
+  scoped_ptr<ChromeUserMetricsRecorder> chrome_user_metrics_recorder_;
+
 #if defined(OS_CHROMEOS)
   scoped_ptr<chromeos::DisplayConfigurationObserver>
       display_configuration_observer_;

chrome/browser/ui/ash/chrome_shell_delegate_chromeos.cc

@@ -217,10 +217,13 @@ void ChromeShellDelegate::PreInit() {
   // in Shell::Init.
   display_configuration_observer_.reset(
       new chromeos::DisplayConfigurationObserver());
+
+  chrome_user_metrics_recorder_.reset(new ChromeUserMetricsRecorder);
 }
 
 void ChromeShellDelegate::PreShutdown() {
   display_configuration_observer_.reset();
+  chrome_user_metrics_recorder_.reset();
 }
 
 ash::SessionStateDelegate* ChromeShellDelegate::CreateSessionStateDelegate() {

chrome/browser/ui/ash/metrics/chrome_user_metrics_recorder.cc

@@ -0,0 +1,47 @@
+// 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/ui/ash/metrics/chrome_user_metrics_recorder.h"
+
+#include "ash/metrics/task_switch_metrics_recorder.h"
+#include "ash/metrics/user_metrics_recorder.h"
+#include "ash/shell.h"
+#include "base/logging.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/host_desktop.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+
+ChromeUserMetricsRecorder::ChromeUserMetricsRecorder() {
+  BrowserList::AddObserver(this);
+}
+
+ChromeUserMetricsRecorder::~ChromeUserMetricsRecorder() {
+  DCHECK(BrowserList::GetInstance(chrome::HOST_DESKTOP_TYPE_ASH)->empty());
+  BrowserList::RemoveObserver(this);
+}
+
+void ChromeUserMetricsRecorder::OnBrowserAdded(Browser* browser) {
+  browser->tab_strip_model()->AddObserver(this);
+}
+
+void ChromeUserMetricsRecorder::OnBrowserRemoved(Browser* browser) {
+  browser->tab_strip_model()->RemoveObserver(this);
+}
+
+void ChromeUserMetricsRecorder::ActiveTabChanged(
+    content::WebContents* old_contents,
+    content::WebContents* new_contents,
+    int index,
+    int reason) {
+  if (reason & CHANGE_REASON_USER_GESTURE)
+    OnTabSwitchedByUserGesture();
+}
+
+void ChromeUserMetricsRecorder::OnTabSwitchedByUserGesture() {
+  ash::Shell::GetInstance()
+      ->metrics()
+      ->task_switch_metrics_recorder()
+      .OnTaskSwitch(ash::TaskSwitchMetricsRecorder::kTabStrip);
+}

chrome/browser/ui/ash/metrics/chrome_user_metrics_recorder.h

@@ -0,0 +1,40 @@
+// 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.
+
+#ifndef CHROME_BROWSER_UI_ASH_METRICS_CHROME_USER_METRICS_RECORDER_H_
+#define CHROME_BROWSER_UI_ASH_METRICS_CHROME_USER_METRICS_RECORDER_H_
+
+#include "base/macros.h"
+#include "chrome/browser/ui/browser_list_observer.h"
+#include "chrome/browser/ui/tabs/tab_strip_model_observer.h"
+
+namespace content {
+class WebContents;
+}  // namespace content
+
+// A bridge proxy between chrome/browser events and ash::UserMetricsRecorder.
+class ChromeUserMetricsRecorder : public chrome::BrowserListObserver,
+                                  public TabStripModelObserver {
+ public:
+  ChromeUserMetricsRecorder();
+  ~ChromeUserMetricsRecorder() override;
+
+  // chrome::BroswerListObserver:
+  void OnBrowserAdded(Browser* browser) override;
+  void OnBrowserRemoved(Browser* browser) override;
+
+  // TabStripModelObserver:
+  void ActiveTabChanged(content::WebContents* old_contents,
+                        content::WebContents* new_contents,
+                        int index,
+                        int reason) override;
+
+ private:
+  // Called when a different tab becomes active due to a user gesture.
+  void OnTabSwitchedByUserGesture();
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeUserMetricsRecorder);
+};
+
+#endif  // CHROME_BROWSER_UI_ASH_METRICS_CHROME_USER_METRICS_RECORDER_H_

chrome/chrome_browser_ui.gypi

@@ -599,6 +599,8 @@
       'browser/ui/ash/launcher/multi_profile_browser_status_monitor.h',
       'browser/ui/ash/media_delegate_chromeos.cc',
       'browser/ui/ash/media_delegate_chromeos.h',
+      'browser/ui/ash/metrics/chrome_user_metrics_recorder.cc',
+      'browser/ui/ash/metrics/chrome_user_metrics_recorder.h',
       'browser/ui/ash/multi_user/multi_user_context_menu_chromeos.cc',
       'browser/ui/ash/multi_user/multi_user_notification_blocker_chromeos.cc',
       'browser/ui/ash/multi_user/multi_user_notification_blocker_chromeos.h',

tools/metrics/histograms/histograms.xml

@@ -785,6 +785,16 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>The duration of mostly stationary long-duration touches.</summary>
 </histogram>
 
+<histogram name="Ash.Tab.TimeBetweenSwitchToExistingTabUserActions"
+    units="seconds">
+  <owner>bruthig@chromium.org</owner>
+  <owner>tdanderson@chromium.org</owner>
+  <summary>
+    The number of seconds between tab switches triggered by a user gesture (e.g.
+    Ctrl+T, Ctrl+1, tapping or clicking the tab strip, etc).
+  </summary>
+</histogram>
+
 <histogram name="Ash.TouchDuration" units="milliseconds">
   <obsolete>
     Deprecated 12/2013 in r239809, and replaced by Ash.TouchDuration2.