Add summary for Backup menu in Settings.

'On'/'Off' depending on whether the backup is enabled in settings.

Refactors BackupSettingsActivity to be shown on System fragment via
xml/PreferenceController instead of category in the manifest.

Bug: 36891827
Test: make RunSettingsRoboTests
Change-Id: I61425fed4d63055c6c386be38792ae074aa72679

tests/robotests/src/com/android/settings/backup/BackupSettingsActivityPreferenceControllerTest.java

@@ -0,0 +1,122 @@
+/*
+ * 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.backup;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.accounts.AccountManager;
+import android.app.backup.BackupManager;
+import android.content.Context;
+import android.content.Intent;
+import android.os.RemoteException;
+import android.os.UserManager;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.R;
+import com.android.settings.SettingsRobolectricTestRunner;
+import com.android.settings.TestConfig;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION,
+        shadows = {BackupSettingsActivityPreferenceControllerTest.ShadowBackupManager.class})
+public class BackupSettingsActivityPreferenceControllerTest {
+    private static final String KEY_BACKUP_SETTINGS = "backup_settings";
+
+    private Context mContext;
+    @Mock
+    private UserManager mUserManager;
+
+    @Mock
+    private PreferenceScreen mScreen;
+    @Mock
+    private Preference mBackupPreference;
+
+    private BackupSettingsActivityPreferenceController mController;
+
+    private static boolean mBackupEnabled;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+        mContext = spy(RuntimeEnvironment.application.getApplicationContext());
+        when(mContext.getSystemService(Context.USER_SERVICE)).thenReturn(mUserManager);
+
+        mController = new BackupSettingsActivityPreferenceController(mContext);
+    }
+
+    @Test
+    public void updateState_backupOn() throws RemoteException {
+        mBackupEnabled = true;
+
+        mController.updateState(mBackupPreference);
+
+        verify(mBackupPreference).setSummary(R.string.accessibility_feature_state_on);
+    }
+
+    @Test
+    public void updateState_backupOff() throws RemoteException {
+        mBackupEnabled = false;
+
+        mController.updateState(mBackupPreference);
+
+        verify(mBackupPreference).setSummary(R.string.accessibility_feature_state_off);
+    }
+
+    @Test
+    public void isAvailable_systemUser() {
+        when(mUserManager.isAdminUser()).thenReturn(true);
+
+        assertThat(mController.isAvailable()).isTrue();
+    }
+
+    @Test
+    public void isAvailable_nonSystemUser() {
+        when(mUserManager.isAdminUser()).thenReturn(false);
+
+        assertThat(mController.isAvailable()).isFalse();
+    }
+
+    @Test
+    public void getPreferenceKey() {
+        assertThat(mController.getPreferenceKey()).isEqualTo(KEY_BACKUP_SETTINGS);
+    }
+
+    @Implements(BackupManager.class)
+    public static class ShadowBackupManager {
+
+        @Implementation
+        public boolean isBackupEnabled() {
+            return mBackupEnabled;
+        }
+    }
+}