Add kill-switch to distinguish chart or non-chart design

Bug: 184807417
Bug: 180607918
Test: make SettingsRoboTests
Test: make SettingsGoogleRoboTests
Change-Id: Iacbb012209d552b58b774f90f5b0aeb60ce6d33d

src/com/android/settings/fuelgauge/BatteryHistoryLoader.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.settings.fuelgauge;
+
+import android.content.Context;
+
+import com.android.settings.overlay.FeatureFactory;
+import com.android.settingslib.utils.AsyncLoaderCompat;
+
+import java.util.List;
+import java.util.Map;
+
+/** Loader that can be used to load battery history information. */
+public class BatteryHistoryLoader
+        extends AsyncLoaderCompat<Map<Long, List<BatteryHistEntry>>> {
+    private static final String TAG = "BatteryHistoryLoader";
+
+    private final Context mContext;
+
+    public BatteryHistoryLoader(Context context) {
+        super(context);
+        mContext = context;
+    }
+
+    @Override
+    protected void onDiscardResult(Map<Long, List<BatteryHistEntry>> result) {
+    }
+
+    @Override
+    public Map<Long, List<BatteryHistEntry>> loadInBackground() {
+        final PowerUsageFeatureProvider powerUsageFeatureProvider =
+            FeatureFactory.getFactory(mContext).getPowerUsageFeatureProvider(mContext);
+        return powerUsageFeatureProvider.getBatteryHistory(mContext);
+    }
+}