Add classloader for RtlCompatibleViewPager

To avoid BadParcelableException when reload the activity after it
is killed by OS.

Bug: 31707097
Test: make SettingsTests && adb install -r \
${OUT}/data/app/SettingsTests/SettingsTests.apk && \
adb shell am instrument -w \
'com.android.settings.tests/android.support.test.runner.AndroidJUnitRunner'

Change-Id: Ic8f20d9e2d236f0bea96071a88fbc6e7ba856f54

src/com/android/settings/widget/RtlCompatibleViewPager.java

@@ -97,8 +97,8 @@ public final class RtlCompatibleViewPager extends ViewPager {
             super(superState);
         }
 
-        private RtlSavedState(Parcel in) {
-            super(in);
+        private RtlSavedState(Parcel in, ClassLoader loader) {
+            super(in, loader);
             position = in.readInt();
         }
 
@@ -108,11 +108,17 @@ public final class RtlCompatibleViewPager extends ViewPager {
             out.writeInt(position);
         }
 
-        public static final Parcelable.Creator<RtlSavedState> CREATOR
-                = new Parcelable.Creator<RtlSavedState>() {
+        public static final Parcelable.ClassLoaderCreator<RtlSavedState> CREATOR
+                = new Parcelable.ClassLoaderCreator<RtlSavedState>() {
+            @Override
+            public RtlSavedState createFromParcel(Parcel source,
+                    ClassLoader loader) {
+                return new RtlSavedState(source, loader);
+            }
+
             @Override
             public RtlSavedState createFromParcel(Parcel in) {
-                return new RtlSavedState(in);
+                return new RtlSavedState(in, null);
             }
 
             @Override

tests/app/src/com/android/settings/tests/SettingsRestoreAfterCloseTest.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2016 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.tests;
+
+import android.app.ActivityManagerNative;
+import android.content.Context;
+import android.content.Intent;
+import android.provider.Settings;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+import android.support.test.uiautomator.By;
+import android.support.test.uiautomator.UiDevice;
+import android.support.test.uiautomator.Until;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class SettingsRestoreAfterCloseTest {
+    private static final String PACKAGE_SETTINGS = "com.android.settings";
+    private static final int TIME_OUT = 2000;
+
+    private boolean mAlwaysFinish;
+
+    @Before
+    public void setUp() throws Exception {
+        // To make sure when we press home button, the activity will be destroyed by OS
+        Context context = InstrumentationRegistry.getContext();
+        mAlwaysFinish = Settings.Global.getInt(
+                context.getContentResolver(), Settings.Global
+                .ALWAYS_FINISH_ACTIVITIES, 0)
+                != 0;
+
+        ActivityManagerNative.getDefault().setAlwaysFinish(true);
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        ActivityManagerNative.getDefault().setAlwaysFinish(mAlwaysFinish);
+    }
+
+    @Test
+    public void testRtlStability_AppCloseAndReOpen_shouldNotCrash() throws Exception {
+
+        final UiDevice uiDevice = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation
+                ());
+        uiDevice.pressHome();
+
+        // Open the settings app
+        startSettingsMainActivity(uiDevice);
+
+        // Press home button
+        uiDevice.pressHome();
+        final String launcherPackage = uiDevice.getLauncherPackageName();
+        uiDevice.wait(Until.hasObject(By.pkg(launcherPackage).depth(0)), TIME_OUT);
+
+        // Open the settings again
+        startSettingsMainActivity(uiDevice);
+    }
+
+    private void startSettingsMainActivity(UiDevice uiDevice) {
+        Context context = InstrumentationRegistry.getContext();
+        context.startActivity(new Intent(android.provider.Settings.ACTION_SETTINGS));
+        uiDevice.wait(Until.hasObject(By.pkg(PACKAGE_SETTINGS).depth(0)), TIME_OUT);
+    }
+}