Correct bug in AppActivityRegistry.

This CL corrects a bug which occurs in the following
situation:
1. Chrome and its web apps are active for X(example 1 hour).
2. Chrome is still active when time limit is changed to anywhere in 0 >
new_limit < X(above).
3. Observe that other web apps are paused where chrome is not.

Bug: 1057724
Change-Id: I1984057fff376e07bf738aaa31e6cc7eb49b5908
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2083630
Commit-Queue: Yilkal Abe <yilkal@chromium.org>
Reviewed-by: Aga Wronska <agawronska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746125}

chrome/browser/chromeos/child_accounts/time_limits/app_activity_registry.cc

@@ -428,8 +428,6 @@ void AppActivityRegistry::SetAppLimit(
     return;
   }
 
-  // TODO(agawronska): Handle web limit changes here.
-
   // Limit for the active app changed - adjust the timers.
   // Handling of active app is different, because ongoing activity needs to be
   // taken into account.
@@ -607,6 +605,11 @@ void AppActivityRegistry::SetAppState(const AppId& app_id, AppState app_state) {
   AppDetails& app_details = activity_registry_.at(app_id);
   AppActivity& app_activity = app_details.activity;
   AppState previous_state = app_activity.app_state();
+
+  // There was no change in state, return.
+  if (previous_state == app_state)
+    return;
+
   app_activity.SetAppState(app_state);
 
   if (app_activity.app_state() == AppState::kLimitReached) {
@@ -700,6 +703,11 @@ void AppActivityRegistry::ScheduleTimeLimitCheckForApp(const AppId& app_id) {
     time_limit = time_limit.value() - kFiveMinutes;
   } else if (time_limit > kOneMinute) {
     time_limit = time_limit.value() - kOneMinute;
+  } else if (time_limit == kZeroMinutes) {
+    // Zero minutes case could be handled by using the timer below, but we call
+    // it explicitly to simplify tests.
+    CheckTimeLimitForApp(app_id);
+    return;
   }
 
   VLOG(1) << "Schedule app time limit check for " << app_id << " for "
@@ -850,13 +858,8 @@ base::TimeDelta AppActivityRegistry::GetWebActiveRunningTime() const {
 void AppActivityRegistry::WebTimeLimitReached(base::Time timestamp) {
   for (auto& app_info : activity_registry_) {
     const AppId& app_id = app_info.first;
-    AppDetails& details = app_info.second;
-    if (!ContributesToWebTimeLimit(app_id, GetAppState(app_id))) {
+    if (!ContributesToWebTimeLimit(app_id, GetAppState(app_id)))
       continue;
-    }
-
-    if (details.activity.app_state() == AppState::kLimitReached)
-      return;
 
     SetAppState(app_id, AppState::kLimitReached);
   }

chrome/browser/chromeos/child_accounts/time_limits/app_activity_registry_unittest.cc

@@ -743,5 +743,26 @@ TEST_F(AppActivityRegistryTest, RemoveOldEntries) {
   }
 }
 
+TEST_F(AppActivityRegistryTest, ActiveWebAppBlocked) {
+  // Create activity for web app.
+  CreateAppActivityForApp(kApp2, base::TimeDelta::FromHours(1));
+
+  // Set Chrome as active.
+  registry().OnChromeAppActivityChanged(ChromeAppActivityState::kActive,
+                                        base::Time::Now());
+
+  // Update the time limits for Chrome.
+  AppLimit chrome_limit(AppRestriction::kTimeLimit,
+                        base::TimeDelta::FromMinutes(30), base::Time::Now());
+
+  std::map<AppId, AppLimit> app_limits = {{GetChromeAppId(), chrome_limit}};
+  registry().UpdateAppLimits(app_limits);
+
+  // Web time limit should be reached.
+  EXPECT_EQ(registry().GetAppState(kApp2), AppState::kLimitReached);
+
+  EXPECT_EQ(registry().GetAppState(GetChromeAppId()), AppState::kLimitReached);
+}
+
 }  // namespace app_time
 }  // namespace chromeos