From 715a70603c1161e6e8f18888df0c346040961b07 Mon Sep 17 00:00:00 2001 From: Yuxin Hu Date: Mon, 1 May 2023 21:48:33 +0000 Subject: [PATCH] Add AndroidJUnitTest for developer option switch Bug: b/270994705 Test: m -j45 atest SettingsRoboTests:GraphicsDriverEnableAngleAsSystemDriverControllerTest atest -c GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest Change-Id: Idbb93458a64894c3eba78a8f9373c40e3ddf35c5 --- ...erEnableAngleAsSystemDriverController.java | 47 ++- ...GraphicsDriverSystemPropertiesWrapper.java | 44 +++ ...ableAngleAsSystemDriverControllerTest.java | 22 +- ...ngleAsSystemDriverControllerJUnitTest.java | 325 ++++++++++++++++++ 4 files changed, 418 insertions(+), 20 deletions(-) create mode 100644 src/com/android/settings/development/graphicsdriver/GraphicsDriverSystemPropertiesWrapper.java create mode 100644 tests/unit/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest.java diff --git a/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java b/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java index b9f34137111..04252fa0d56 100644 --- a/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java +++ b/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java @@ -48,6 +48,8 @@ public class GraphicsDriverEnableAngleAsSystemDriverController private final DevelopmentSettingsDashboardFragment mFragment; + private final GraphicsDriverSystemPropertiesWrapper mSystemProperties; + @VisibleForTesting static final String PROPERTY_RO_GFX_ANGLE_SUPPORTED = "ro.gfx.angle.supported"; @@ -57,11 +59,34 @@ public class GraphicsDriverEnableAngleAsSystemDriverController @VisibleForTesting static final String ANGLE_DRIVER_SUFFIX = "angle"; + @VisibleForTesting + static class Injector { + public GraphicsDriverSystemPropertiesWrapper createSystemPropertiesWrapper() { + return new GraphicsDriverSystemPropertiesWrapper() { + @Override + public String get(String key, String def) { + return SystemProperties.get(key, def); + } + + @Override + public void set(String key, String val) { + SystemProperties.set(key, val); + } + }; + } + } public GraphicsDriverEnableAngleAsSystemDriverController( Context context, DevelopmentSettingsDashboardFragment fragment) { + this(context, fragment, new Injector()); + } + + @VisibleForTesting + GraphicsDriverEnableAngleAsSystemDriverController( + Context context, DevelopmentSettingsDashboardFragment fragment, Injector injector) { super(context); mFragment = fragment; + mSystemProperties = injector.createSystemPropertiesWrapper(); } @Override @@ -76,20 +101,27 @@ public class GraphicsDriverEnableAngleAsSystemDriverController // set "persist.graphics.egl" to "" if enableAngleAsSystemDriver is false GraphicsEnvironment.getInstance().toggleAngleAsSystemDriver(enableAngleAsSystemDriver); // pop up a window asking user to reboot to make the new "persist.graphics.egl" take effect + showRebootDialog(); + return true; + } + + @VisibleForTesting + void showRebootDialog() { RebootConfirmationDialogFragment.show( mFragment, R.string.reboot_dialog_enable_angle_as_system_driver, R.string.cancel, this); - return true; } + @Override public void updateState(Preference preference) { // set switch on if "persist.graphics.egl" is "angle" and angle is built in /vendor // set switch off otherwise. - final String currentGlesDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL); + final String currentGlesDriver = + mSystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL, ""); final boolean isAngle = TextUtils.equals(ANGLE_DRIVER_SUFFIX, currentGlesDriver); - final boolean isAngleSupported = - TextUtils.equals(SystemProperties.get(PROPERTY_RO_GFX_ANGLE_SUPPORTED), "true"); + final boolean isAngleSupported = TextUtils + .equals(mSystemProperties.get(PROPERTY_RO_GFX_ANGLE_SUPPORTED, ""), "true"); ((SwitchPreference) mPreference).setChecked(isAngle && isAngleSupported); ((SwitchPreference) mPreference).setEnabled(isAngleSupported); } @@ -98,8 +130,8 @@ public class GraphicsDriverEnableAngleAsSystemDriverController protected void onDeveloperOptionsSwitchEnabled() { // only enable the switch if ro.gfx.angle.supported is true // we use ro.gfx.angle.supported to indicate if ANGLE libs are installed under /vendor - final boolean isAngleSupported = - TextUtils.equals(SystemProperties.get(PROPERTY_RO_GFX_ANGLE_SUPPORTED), "true"); + final boolean isAngleSupported = TextUtils + .equals(mSystemProperties.get(PROPERTY_RO_GFX_ANGLE_SUPPORTED, ""), "true"); ((SwitchPreference) mPreference).setEnabled(isAngleSupported); } @@ -116,7 +148,8 @@ public class GraphicsDriverEnableAngleAsSystemDriverController @Override public void onRebootCancelled() { // if user presses button "Cancel", do not reboot the device, and toggles switch back - final String currentGlesDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL); + final String currentGlesDriver = + mSystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL, ""); if (TextUtils.equals(ANGLE_DRIVER_SUFFIX, currentGlesDriver)) { // if persist.graphics.egl = "angle", set the property value back to "" GraphicsEnvironment.getInstance().toggleAngleAsSystemDriver(false); diff --git a/src/com/android/settings/development/graphicsdriver/GraphicsDriverSystemPropertiesWrapper.java b/src/com/android/settings/development/graphicsdriver/GraphicsDriverSystemPropertiesWrapper.java new file mode 100644 index 00000000000..549cd81c565 --- /dev/null +++ b/src/com/android/settings/development/graphicsdriver/GraphicsDriverSystemPropertiesWrapper.java @@ -0,0 +1,44 @@ +/* + * Copyright (C) 2023 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.development.graphicsdriver; +import android.annotation.NonNull; +import android.annotation.Nullable; +import android.os.SystemProperties; +/** + * Wrapper interface to access {@link SystemProperties}. + * + * @hide + */ +interface GraphicsDriverSystemPropertiesWrapper { + /** + * Get the String value for the given {@code key}. + * + * @param key the key to lookup + * @param def the default value in case the property is not set or empty + * @return if the {@code key} isn't found, return {@code def} if it isn't null, or an empty + * string otherwise + */ + @NonNull + String get(@NonNull String key, @Nullable String def); + /** + * Set the value for the given {@code key} to {@code val}. + * + * @throws IllegalArgumentException if the {@code val} exceeds 91 characters + * @throws RuntimeException if the property cannot be set, for example, if it was blocked by + * SELinux. libc will log the underlying reason. + */ + void set(@NonNull String key, @Nullable String val); +} diff --git a/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java b/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java index 314f8c38091..de380c40c8e 100644 --- a/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java +++ b/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java @@ -81,9 +81,10 @@ public class GraphicsDriverEnableAngleAsSystemDriverControllerTest { // since GraphicsEnvironment is mocked in Robolectric test environment, // we will override the system property persist.graphics.egl as if it is changed by // mGraphicsEnvironment.toggleAngleAsSystemDriver(true). - // TODO: b/270994705 yuxinhu: - // add test coverage to test mGraphicsEnvironment.toggleAngleAsSystemDriver() - // works properly on Android devices / emulators. + + // for test that actually verifies mGraphicsEnvironment.toggleAngleAsSystemDriver(true) + // on a device/emulator, please refer to + // GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest ShadowSystemProperties.override(PROPERTY_PERSISTENT_GRAPHICS_EGL, ANGLE_DRIVER_SUFFIX); mController.onPreferenceChange(mPreference, true); final String systemEGLDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL); @@ -97,9 +98,10 @@ public class GraphicsDriverEnableAngleAsSystemDriverControllerTest { // since GraphicsEnvironment is mocked in Robolectric test environment, // we will override the system property persist.graphics.egl as if it is changed by // mGraphicsEnvironment.toggleAngleAsSystemDriver(false). - // TODO: b/270994705 yuxinhu: - // add test coverage to test mGraphicsEnvironment.toggleAngleAsSystemDriver() - // works properly on Android devices / emulators. + + // for test that actually verifies mGraphicsEnvironment.toggleAngleAsSystemDriver(true) + // on a device/emulator, please refer to + // GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest ShadowSystemProperties.override(PROPERTY_PERSISTENT_GRAPHICS_EGL, ""); mController.onPreferenceChange(mPreference, false); final String systemEGLDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL); @@ -124,20 +126,14 @@ public class GraphicsDriverEnableAngleAsSystemDriverControllerTest { @Test public void updateState_angleSupported_angleUsed_preferenceShouldBeChecked() { ShadowSystemProperties.override(PROPERTY_RO_GFX_ANGLE_SUPPORTED, "true"); - // TODO: b/270994705 yuxinhu: - // add test coverage to test mGraphicsEnvironment.toggleAngleAsSystemDriver() - // works properly on Android devices / emulators. ShadowSystemProperties.override(PROPERTY_PERSISTENT_GRAPHICS_EGL, ANGLE_DRIVER_SUFFIX); mController.updateState(mPreference); - verify(mPreference).setChecked(true); //false + verify(mPreference).setChecked(true); } @Test public void updateState_angleSupported_angleNotUsed_preferenceShouldNotBeChecked() { ShadowSystemProperties.override(PROPERTY_RO_GFX_ANGLE_SUPPORTED, "true"); - // TODO: b/270994705 yuxinhu: - // add test coverage to test mGraphicsEnvironment.toggleAngleAsSystemDriver(false) - // works properly on Android devices / emulators. ShadowSystemProperties.override(PROPERTY_PERSISTENT_GRAPHICS_EGL, ""); mController.updateState(mPreference); verify(mPreference).setChecked(false); diff --git a/tests/unit/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest.java b/tests/unit/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest.java new file mode 100644 index 00000000000..3f85535df53 --- /dev/null +++ b/tests/unit/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest.java @@ -0,0 +1,325 @@ +/* + * Copyright (C) 2023 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.development.graphicsdriver; + +import static com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController.ANGLE_DRIVER_SUFFIX; +import static com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController.Injector; +import static com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController.PROPERTY_PERSISTENT_GRAPHICS_EGL; +import static com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController.PROPERTY_RO_GFX_ANGLE_SUPPORTED; + +import static com.google.common.truth.Truth.assertThat; + +import static org.mockito.ArgumentMatchers.any; +import static org.mockito.ArgumentMatchers.eq; +import static org.mockito.Mockito.when; + +import android.content.Context; +import android.os.Looper; +import android.os.SystemProperties; + +import androidx.preference.PreferenceManager; +import androidx.preference.PreferenceScreen; +import androidx.preference.SwitchPreference; +import androidx.test.core.app.ApplicationProvider; +import androidx.test.ext.junit.runners.AndroidJUnit4; + +import com.android.settings.development.DevelopmentSettingsDashboardFragment; + +import org.junit.Assert; +import org.junit.Before; +import org.junit.Test; +import org.junit.runner.RunWith; +import org.mockito.Mock; +import org.mockito.MockitoAnnotations; + +import java.util.concurrent.CountDownLatch; +import java.util.concurrent.TimeUnit; + +@RunWith(AndroidJUnit4.class) +public class GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest { + private Context mContext; + private SwitchPreference mPreference; + + private GraphicsDriverEnableAngleAsSystemDriverController mController; + + @Mock + private DevelopmentSettingsDashboardFragment mFragment; + + @Mock + private GraphicsDriverSystemPropertiesWrapper mSystemPropertiesMock; + + @Before + public void setUp() { + MockitoAnnotations.initMocks(this); + if (Looper.myLooper() == null) { + Looper.prepare(); + } + + mContext = ApplicationProvider.getApplicationContext(); + + // Construct a GraphicsDriverEnableAngleAsSystemDriverController with two Overrides: + // 1) Override the mSystemProperties with mSystemPropertiesMock, + // so we can force the SystemProperties with values we need to run tests. + // 2) Override the showRebootDialog() to do nothing. + // We do not need to pop up the reboot dialog in the test. + mController = new GraphicsDriverEnableAngleAsSystemDriverController( + mContext, mFragment, new Injector(){ + @Override + public GraphicsDriverSystemPropertiesWrapper createSystemPropertiesWrapper() { + return mSystemPropertiesMock; + } + }) { + @Override + void showRebootDialog() { + // do nothing + } + }; + + final PreferenceManager preferenceManager = new PreferenceManager(mContext); + final PreferenceScreen screen = preferenceManager.createPreferenceScreen(mContext); + mPreference = new SwitchPreference(mContext); + mPreference.setKey(mController.getPreferenceKey()); + screen.addPreference(mPreference); + mController.displayPreference(screen); + } + + @Test + public void onPreferenceChange_switchOn_shouldEnableAngleAsSystemDriver() { + // Add a callback when SystemProperty changes. + // This allows the thread to wait until + // GpuService::toggleAngleAsSystemDriver() updates the persist.graphics.egl. + final CountDownLatch countDownLatch = new CountDownLatch(1); + Runnable countDown = new Runnable() { + @Override + public void run() { + countDownLatch.countDown(); + } + }; + SystemProperties.addChangeCallback(countDown); + + // Test onPreferenceChange(true) updates the persist.graphics.egl to "angle" + mController.onPreferenceChange(mPreference, true); + try { + countDownLatch.await(100, TimeUnit.MILLISECONDS); + } catch (InterruptedException e) { + Assert.fail(e.getMessage()); + } + final String systemEGLDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL); + assertThat(systemEGLDriver).isEqualTo(ANGLE_DRIVER_SUFFIX); + + // Done with the test, remove the callback + SystemProperties.removeChangeCallback(countDown); + } + + @Test + public void onPreferenceChange_switchOff_shouldDisableAngleAsSystemDriver() { + // Add a callback when SystemProperty changes. + // This allows the thread to wait until + // GpuService::toggleAngleAsSystemDriver() updates the persist.graphics.egl. + final CountDownLatch countDownLatch = new CountDownLatch(1); + Runnable countDown = new Runnable() { + @Override + public void run() { + countDownLatch.countDown(); + } + }; + SystemProperties.addChangeCallback(countDown); + + // Test onPreferenceChange(false) updates the persist.graphics.egl to "" + mController.onPreferenceChange(mPreference, false); + try { + countDownLatch.await(100, TimeUnit.MILLISECONDS); + } catch (InterruptedException e) { + Assert.fail(e.getMessage()); + } + final String systemEGLDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL); + assertThat(systemEGLDriver).isEqualTo(""); + + // Done with the test, remove the callback + SystemProperties.removeChangeCallback(countDown); + } + + @Test + public void updateState_angleNotSupported_PreferenceShouldDisabled() { + when(mSystemPropertiesMock.get(eq(PROPERTY_RO_GFX_ANGLE_SUPPORTED), any())).thenReturn(""); + mController.updateState(mPreference); + assertThat(mPreference.isEnabled()).isFalse(); + } + + @Test + public void updateState_angleNotSupported_PreferenceShouldNotBeChecked() { + when(mSystemPropertiesMock.get(eq(PROPERTY_RO_GFX_ANGLE_SUPPORTED), any())) + .thenReturn(""); + mController.updateState(mPreference); + assertThat(mPreference.isChecked()).isFalse(); + } + + @Test + public void updateState_angleSupported_PreferenceShouldEnabled() { + when(mSystemPropertiesMock.get(eq(PROPERTY_RO_GFX_ANGLE_SUPPORTED), any())) + .thenReturn("true"); + mController.updateState(mPreference); + assertThat(mPreference.isEnabled()).isTrue(); + } + + @Test + public void updateState_angleSupported_angleIsSystemGLESDriver_PreferenceShouldBeChecked() { + when(mSystemPropertiesMock.get(eq(PROPERTY_RO_GFX_ANGLE_SUPPORTED), any())) + .thenReturn("true"); + when(mSystemPropertiesMock.get(eq(PROPERTY_PERSISTENT_GRAPHICS_EGL), any())) + .thenReturn(ANGLE_DRIVER_SUFFIX); + mController.updateState(mPreference); + assertThat(mPreference.isChecked()).isTrue(); + } + + @Test + public void + updateState_angleSupported_angleIsNotSystemGLESDriver_PreferenceShouldNotBeChecked() { + when(mSystemPropertiesMock.get(eq(PROPERTY_RO_GFX_ANGLE_SUPPORTED), any())) + .thenReturn("true"); + when(mSystemPropertiesMock.get(eq(PROPERTY_PERSISTENT_GRAPHICS_EGL), any())) + .thenReturn(""); + mController.updateState(mPreference); + assertThat(mPreference.isChecked()).isFalse(); + } + + @Test + public void onDeveloperOptionSwitchEnabled_angleSupported_PreferenceShouldEnabled() { + when(mSystemPropertiesMock.get(eq(PROPERTY_RO_GFX_ANGLE_SUPPORTED), any())) + .thenReturn("true"); + mController.onDeveloperOptionsSwitchEnabled(); + assertThat(mPreference.isEnabled()).isTrue(); + } + + @Test + public void onDeveloperOptionSwitchEnabled_angleNotSupported_PrefenceShouldDisabled() { + when(mSystemPropertiesMock.get(eq(PROPERTY_RO_GFX_ANGLE_SUPPORTED), any())) + .thenReturn("false"); + mController.onDeveloperOptionsSwitchEnabled(); + assertThat(mPreference.isEnabled()).isFalse(); + } + + @Test + public void onDeveloperOptionSwitchDisabled_angleIsNotSystemGLESDriver() { + // Add a callback when SystemProperty changes. + // This allows the thread to wait until + // GpuService::toggleAngleAsSystemDriver() updates the persist.graphics.egl. + final CountDownLatch countDownLatch = new CountDownLatch(1); + Runnable countDown = new Runnable() { + @Override + public void run() { + countDownLatch.countDown(); + } + }; + SystemProperties.addChangeCallback(countDown); + + // Test that onDeveloperOptionSwitchDisabled, + // persist.graphics.egl updates to "" + mController.onDeveloperOptionsSwitchDisabled(); + try { + countDownLatch.await(100, TimeUnit.MILLISECONDS); + } catch (InterruptedException e) { + Assert.fail(e.getMessage()); + } + final String systemEGLDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL); + assertThat(systemEGLDriver).isEqualTo(""); + + // Done with the test, remove the callback + SystemProperties.removeChangeCallback(countDown); + } + + @Test + public void onDeveloperOptionSwitchDisabled_PreferenceShouldNotBeChecked() { + mController.onDeveloperOptionsSwitchDisabled(); + assertThat(mPreference.isChecked()).isFalse(); + } + + @Test + public void onDeveloperOptionSwitchDisabled_PreferenceShouldDisabled() { + mController.onDeveloperOptionsSwitchDisabled(); + assertThat(mPreference.isEnabled()).isFalse(); + } + + @Test + public void onRebootCancelled_ToggleSwitchFromOnToOff() { + // Add a callback when SystemProperty changes. + // This allows the thread to wait until + // GpuService::toggleAngleAsSystemDriver() updates the persist.graphics.egl. + final CountDownLatch countDownLatch = new CountDownLatch(1); + Runnable countDown = new Runnable() { + @Override + public void run() { + countDownLatch.countDown(); + } + }; + SystemProperties.addChangeCallback(countDown); + + // Test that if the current persist.graphics.egl is "angle", + // when reboot is cancelled, persist.graphics.egl is changed back to "", + // and switch is set to unchecked. + when(mSystemPropertiesMock.get(eq(PROPERTY_PERSISTENT_GRAPHICS_EGL), any())) + .thenReturn(ANGLE_DRIVER_SUFFIX); + mController.onRebootCancelled(); + try { + countDownLatch.await(100, TimeUnit.MILLISECONDS); + } catch (InterruptedException e) { + Assert.fail(e.getMessage()); + } + + final String systemEGLDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL); + assertThat(systemEGLDriver).isEqualTo(""); + assertThat(mPreference.isChecked()).isFalse(); + + // Done with the test, remove the callback. + SystemProperties.removeChangeCallback(countDown); + } + + @Test + public void onRebootCancelled_ToggleSwitchFromOffToOn() { + // Add a callback when SystemProperty changes. + // This allows the thread to wait until + // GpuService::toggleAngleAsSystemDriver() updates the persist.graphics.egl. + final CountDownLatch countDownLatch = new CountDownLatch(1); + Runnable countDown = new Runnable() { + @Override + public void run() { + countDownLatch.countDown(); + } + }; + SystemProperties.addChangeCallback(countDown); + + // Test that if the current persist.graphics.egl is "", + // when reboot is cancelled, persist.graphics.egl is changed back to "angle", + // and switch is set to checked. + when(mSystemPropertiesMock.get(eq(PROPERTY_PERSISTENT_GRAPHICS_EGL), any())) + .thenReturn(""); + mController.onRebootCancelled(); + try { + countDownLatch.await(100, TimeUnit.MILLISECONDS); + } catch (InterruptedException e) { + Assert.fail(e.getMessage()); + } + + final String systemEGLDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL); + assertThat(systemEGLDriver).isEqualTo(ANGLE_DRIVER_SUFFIX); + assertThat(mPreference.isChecked()).isTrue(); + + // Done with the test, remove the callback. + SystemProperties.removeChangeCallback(countDown); + } + +}