Fix case in which onTaskStackChanged was not called

In completeResumeLocked, visibility was changed but we didn't set the
flag so the listeners didn't get notified.

Test:
runtest -c com.android.server.am.TaskStackChangedListenerTest frameworks-services

Change-Id: I4b4076a895baafc877f312d24211a2fc69a98e3b
Fixes: 31527783

services/core/java/com/android/server/am/ActivityStack.java

@@ -1414,7 +1414,12 @@ final class ActivityStack {
      * this function updates the rest of our state to match that fact.
      */
     private void completeResumeLocked(ActivityRecord next) {
+        boolean wasVisible = next.visible;
         next.visible = true;
+        if (!wasVisible) {
+            // Visibility has changed, so take a note of it so we call the TaskStackChangedListener
+            mStackSupervisor.mAppVisibilitiesChangedSinceLastPause = true;
+        }
         next.idle = false;
         next.results = null;
         next.newIntents = null;

services/tests/servicestests/Android.mk

@@ -53,6 +53,8 @@ ifeq (true,$(EMMA_INSTRUMENT))
 LOCAL_JACK_FLAGS := --multi-dex native
 endif # EMMA_INSTRUMENT_STATIC
 
+LOCAL_STATIC_JAVA_LIBRARIES += ub-uiautomator
+
 include $(BUILD_PACKAGE)
 
 #########################################################################

services/tests/servicestests/AndroidManifest.xml

@@ -43,6 +43,7 @@
     <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
     <uses-permission android:name="android.permission.PACKET_KEEPALIVE_OFFLOAD" />
     <uses-permission android:name="android.permission.GET_INTENT_SENDER_INTENT" />
+    <uses-permission android:name="android.permission.MANAGE_ACTIVITY_STACKS" />
 
     <application>
         <uses-library android:name="android.test.runner" />
@@ -155,6 +156,9 @@
             </intent-filter>
         </activity-alias>
 
+        <activity android:name="com.android.server.am.TaskStackChangedListenerTest$ActivityA" />
+        <activity android:name="com.android.server.am.TaskStackChangedListenerTest$ActivityB" />
+
     </application>
 
     <instrumentation

services/tests/servicestests/src/com/android/server/am/TaskStackChangedListenerTest.java

@@ -0,0 +1,123 @@
+/*
+ * 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.server.am;
+
+import static android.support.test.InstrumentationRegistry.getInstrumentation;
+
+import android.app.Activity;
+import android.app.ActivityManagerNative;
+import android.app.IActivityManager;
+import android.app.ITaskStackListener;
+import android.content.Context;
+import android.content.Intent;
+import android.os.RemoteException;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.filters.MediumTest;
+import android.support.test.runner.AndroidJUnit4;
+import android.support.test.uiautomator.UiDevice;
+
+import com.android.internal.annotations.GuardedBy;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@MediumTest
+@RunWith(AndroidJUnit4.class)
+public class TaskStackChangedListenerTest extends ITaskStackListener.Stub {
+
+    private IActivityManager mService;
+
+    private static final Object sLock = new Object();
+    @GuardedBy("sLock")
+    private static boolean sTaskStackChangedCalled;
+    private static boolean sActivityBResumed;
+
+    @Before
+    public void setUp() throws Exception {
+        mService = ActivityManagerNative.getDefault();
+        mService.registerTaskStackListener(this);
+    }
+
+    @Test
+    public void testTaskStackChanged_afterFinish() throws Exception {
+        Context ctx = InstrumentationRegistry.getContext();
+        ctx.startActivity(new Intent(ctx, ActivityA.class));
+        UiDevice.getInstance(getInstrumentation()).waitForIdle();
+        synchronized (sLock) {
+            Assert.assertTrue(sTaskStackChangedCalled);
+        }
+        Assert.assertTrue(sActivityBResumed);
+    }
+
+    @Override
+    public void onTaskStackChanged() throws RemoteException {
+        synchronized (sLock) {
+            sTaskStackChangedCalled = true;
+        }
+    }
+
+    @Override
+    public void onActivityPinned() throws RemoteException {
+    }
+
+    @Override
+    public void onPinnedActivityRestartAttempt() throws RemoteException {
+    }
+
+    @Override
+    public void onPinnedStackAnimationEnded() throws RemoteException {
+    }
+
+    @Override
+    public void onActivityForcedResizable(String packageName, int taskId) throws RemoteException {
+    }
+
+    @Override
+    public void onActivityDismissingDockedStack() throws RemoteException {
+    }
+
+    public static class ActivityA extends Activity {
+
+        private boolean mActivityBLaunched = false;
+
+        @Override
+        protected void onPostResume() {
+            super.onPostResume();
+            if (mActivityBLaunched) {
+                return;
+            }
+            mActivityBLaunched = true;
+            finish();
+            startActivity(new Intent(this, ActivityB.class));
+        }
+    }
+
+    public static class ActivityB extends Activity {
+
+        @Override
+        protected void onPostResume() {
+            super.onPostResume();
+            synchronized (sLock) {
+                sTaskStackChangedCalled = false;
+            }
+            sActivityBResumed = true;
+            finish();
+        }
+    }
+}