Don't warmup the app list if it hasn't been used in the past 28 days. [Win]

This CL adds a pref that tracks when the app list is last launched and
doesn't warm up the app list on Windows unless the app list has been
launched in the last 28 days.

BUG=440224

Review URL: https://codereview.chromium.org/1016503006

Cr-Commit-Position: refs/heads/master@{#324018}

chrome/browser/ui/app_list/app_list_service.cc

@@ -145,6 +145,7 @@ void AppListService::RegisterPrefs(PrefRegistrySimple* registry) {
   registry->RegisterIntegerPref(prefs::kAppListEnableMethod,
                                 ENABLE_NOT_RECORDED);
   registry->RegisterInt64Pref(prefs::kAppListEnableTime, 0);
+  registry->RegisterInt64Pref(prefs::kAppListLastLaunchTime, 0);
 
 #if defined(OS_MACOSX)
   registry->RegisterIntegerPref(prefs::kAppLauncherShortcutVersion, 0);

chrome/browser/ui/app_list/app_list_service_impl.cc

@@ -213,6 +213,7 @@ void AppListServiceImpl::RecordAppListLaunch() {
                             prefs::kAppListLaunchCount,
                             &SendAppListLaunch);
   RecordAppListDiscoverability(local_state_, false);
+  RecordAppListLastLaunch();
 }
 
 // static
@@ -222,6 +223,19 @@ void AppListServiceImpl::RecordAppListAppLaunch() {
                             &SendAppListAppLaunch);
 }
 
+// static
+void AppListServiceImpl::RecordAppListLastLaunch() {
+  if (!g_browser_process)
+    return;  // In a unit test.
+
+  PrefService* local_state = g_browser_process->local_state();
+  if (!local_state)
+    return;  // In a unit test.
+
+  local_state->SetInt64(prefs::kAppListLastLaunchTime,
+                        base::Time::Now().ToInternalValue());
+}
+
 // static
 void AppListServiceImpl::SendAppListStats() {
   if (!g_browser_process || g_browser_process->IsShuttingDown())

chrome/browser/ui/app_list/app_list_service_impl.h

@@ -45,6 +45,7 @@ class AppListServiceImpl : public AppListService,
 
   void RecordAppListLaunch();
   static void RecordAppListAppLaunch();
+  static void RecordAppListLastLaunch();
 
   // AppListService overrides:
   void SetAppListNextPaintCallback(void (*callback)()) override;

chrome/browser/ui/views/app_list/win/app_list_service_win.cc

@@ -72,6 +72,8 @@ void AppListService::InitAll(Profile* initial_profile,
 
 namespace {
 
+const int kUnusedAppListNoWarmupDays = 28;
+
 int GetAppListIconIndex() {
   BrowserDistribution* dist = BrowserDistribution::GetDistribution();
   return dist->GetIconIndex(BrowserDistribution::SHORTCUT_APP_LAUNCHER);
@@ -356,6 +358,21 @@ bool AppListServiceWin::IsWarmupNeeded() {
     return false;
   }
 
+  // Don't warm up the app list if it hasn't been used for a while. If the last
+  // launch is unknown, record it as "used" on the first warmup.
+  PrefService* local_state = g_browser_process->local_state();
+  int64 last_launch_time_pref =
+      local_state->GetInt64(prefs::kAppListLastLaunchTime);
+  if (last_launch_time_pref == 0)
+    RecordAppListLastLaunch();
+
+  base::Time last_launch_time =
+      base::Time::FromInternalValue(last_launch_time_pref);
+  if (base::Time::Now() - last_launch_time >
+      base::TimeDelta::FromDays(kUnusedAppListNoWarmupDays)) {
+    return false;
+  }
+
   // We only need to initialize the view if there's no view already created and
   // there's no profile loading to be shown.
   return !shower().HasView() && !profile_loader().IsAnyProfileLoading();

chrome/common/pref_names.cc

@@ -2179,6 +2179,9 @@ const char kAppListEnableMethod[] = "app_list.how_enabled";
 // The time that the app launcher was enabled. Cleared when UMA is recorded.
 const char kAppListEnableTime[] = "app_list.when_enabled";
 
+// The last time the app list was launched.
+const char kAppListLastLaunchTime[] = "app_list.last_launch";
+
 // Integer representing the version of the app launcher shortcut installed on
 // the system. Incremented, e.g., when embedded icons change.
 const char kAppLauncherShortcutVersion[] = "apps.app_launcher.shortcut_version";

chrome/common/pref_names.h

@@ -784,6 +784,7 @@ extern const char kAppListAppLaunchCount[];
 extern const char kAppLauncherHasBeenEnabled[];
 extern const char kAppListEnableMethod[];
 extern const char kAppListEnableTime[];
+extern const char kAppListLastLaunchTime[];
 extern const char kAppLauncherShortcutVersion[];
 extern const char kShowAppLauncherPromo[];
 extern const char kAppLauncherDriveAppMapping[];