Don't init batterystats in onCreate()

After ag/2573096, the batterystats will be refreshed after each
broadcastReceiver registeration. And this registeration happens
in onResume().

So we don't need to init batterystats in onCreate() anymore.

Bug: 65629008
Test: RunSettingsRoboTests
Change-Id: I4ed2d420c6f2bb77d726dac4dd58fa6704ce6929

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

@@ -60,8 +60,6 @@ public abstract class PowerUsageBase extends DashboardFragment
         mBatteryBroadcastReceiver.setBatteryChangedListener(() -> {
             restartBatteryStatsLoader();
         });
-
-        getLoaderManager().initLoader(0, icicle, this);
     }
 
     @Override

tests/robotests/src/com/android/settings/fuelgauge/PowerUsageBaseTest.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2017 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 static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyInt;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+import android.app.Activity;
+import android.app.LoaderManager;
+import android.content.Context;
+import android.os.Bundle;
+
+import com.android.internal.os.BatteryStatsHelper;
+import com.android.settings.TestConfig;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+import com.android.settings.testutils.shadow.ShadowDashboardFragment;
+import com.android.settingslib.core.AbstractPreferenceController;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+
+import java.util.List;
+
+/**
+ * Unit tests for {@link PowerUsageBase}.
+ */
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION,
+        shadows = ShadowDashboardFragment.class)
+public class PowerUsageBaseTest {
+    @Mock
+    private BatteryStatsHelper mBatteryStatsHelper;
+    @Mock
+    private LoaderManager mLoaderManager;
+    private TestFragment mFragment;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mFragment = spy(new TestFragment());
+        mFragment.setBatteryStatsHelper(mBatteryStatsHelper);
+        doReturn(mLoaderManager).when(mFragment).getLoaderManager();
+    }
+
+    @Test
+    public void testOnCreate_batteryStatsLoaderNotInvoked() {
+        mFragment.onCreate(null);
+
+        verify(mLoaderManager, never()).initLoader(anyInt(), any(Bundle.class), any());
+    }
+
+    public static class TestFragment extends PowerUsageBase {
+
+        @Override
+        public int getMetricsCategory() {
+            return 0;
+        }
+
+        @Override
+        protected void refreshUi() {
+            // Do nothing
+        }
+
+        @Override
+        protected String getLogTag() {
+            return null;
+        }
+
+        @Override
+        protected int getPreferenceScreenResId() {
+            return 0;
+        }
+
+        @Override
+        protected List<AbstractPreferenceController> getPreferenceControllers(Context context) {
+            return null;
+        }
+
+        public void setBatteryStatsHelper(BatteryStatsHelper batteryStatsHelper) {
+            mStatsHelper = batteryStatsHelper;
+        }
+    }
+}

tests/robotests/src/com/android/settings/testutils/shadow/ShadowDashboardFragment.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2017 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.testutils.shadow;
+
+import android.os.Bundle;
+
+import com.android.settings.dashboard.DashboardFragment;
+
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+
+/**
+ * Shadow of {@link DashboardFragment}.
+ *
+ * Override the {@link #onCreate(Bundle)} to skip a null pointer exception in
+ * {@link android.content.res.Resources.Theme}, which we cannot mock it.
+ */
+@Implements(DashboardFragment.class)
+public class ShadowDashboardFragment {
+
+    @Implementation
+    public void onCreate(Bundle icicle) {
+        // do nothing
+    }
+}