Remove no reference code

- Remove ControllerTask and ControllerFutureTask.
- Remove ControllerTaskTest and ControllerFutureTaskTest.

Fixes: 222661474
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.dashboard
Change-Id: I36f4e723c40aa59ecb3b087cab11f2a744540812

src/com/android/settings/dashboard/DashboardFragment.java

@@ -48,7 +48,6 @@ import com.android.settingslib.drawer.DashboardCategory;
 import com.android.settingslib.drawer.ProviderTile;
 import com.android.settingslib.drawer.Tile;
 import com.android.settingslib.search.Indexable;
-import com.android.settingslib.utils.ThreadUtils;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -58,7 +57,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
-import java.util.concurrent.ExecutionException;
 
 /**
  * Base fragment for dashboard style UI containing a list of static and dynamic setting items.
@@ -222,7 +220,7 @@ public abstract class DashboardFragment extends SettingsPreferenceFragment
         super.onResume();
         updatePreferenceStates();
         writeElapsedTimeMetric(SettingsEnums.ACTION_DASHBOARD_VISIBLE_TIME,
-                "isParalleledControllers:" + isParalleledControllers());
+                "isParalleledControllers:false");
     }
 
     @Override
@@ -348,14 +346,6 @@ public abstract class DashboardFragment extends SettingsPreferenceFragment
                 controller -> controller.displayPreference(screen));
     }
 
-    /**
-     * @return {@code true} if the underlying controllers should be executed in parallel.
-     * Override this function to enable/disable the behavior.
-     */
-    protected boolean isParalleledControllers() {
-        return false;
-    }
-
     /**
      * Get current PreferenceController(s)
      */
@@ -394,36 +384,6 @@ public abstract class DashboardFragment extends SettingsPreferenceFragment
         }
     }
 
-    /**
-     * Use parallel method to update state of each preference managed by PreferenceController.
-     */
-    @VisibleForTesting
-    // To use this parallel approach will cause the side effect of the UI flicker. Such as
-    // the thumb sliding of the toggle button.
-    void updatePreferenceStatesInParallel() {
-        final PreferenceScreen screen = getPreferenceScreen();
-        final Collection<List<AbstractPreferenceController>> controllerLists =
-                mPreferenceControllers.values();
-        final List<ControllerFutureTask> taskList = new ArrayList<>();
-        for (List<AbstractPreferenceController> controllerList : controllerLists) {
-            for (AbstractPreferenceController controller : controllerList) {
-                final ControllerFutureTask task = new ControllerFutureTask(
-                        new ControllerTask(controller, screen, mMetricsFeatureProvider,
-                                getMetricsCategory()), null /* result */);
-                taskList.add(task);
-                ThreadUtils.postOnBackgroundThread(task);
-            }
-        }
-
-        for (ControllerFutureTask task : taskList) {
-            try {
-                task.get();
-            } catch (InterruptedException | ExecutionException e) {
-                Log.w(TAG, task.getController().getPreferenceKey() + " " + e.getMessage());
-            }
-        }
-    }
-
     /**
      * Refresh all preference items, including both static prefs from xml, and dynamic items from
      * DashboardCategory.