Merge "Ignore non-existent displays in #topRunningActivityLocked." into pi-dev

        for (int i = mTmpOrderedDisplayIds.size() - 1; i >= 0; --i) {

            final int displayId = mTmpOrderedDisplayIds.get(i);

            final ActivityDisplay display = mActivityDisplays.get(displayId);

            // If WindowManagerService has encountered the display before we have, ignore as there

            // will be no stacks present and therefore no activities.

            if (display == null) {

                continue;

            }

            for (int j = display.getChildCount() - 1; j >= 0; --j) {

                final ActivityStack stack = display.getChildAt(j);

                if (stack != focusedStack && stack.isTopStackOnDisplay() && stack.isFocusable()) {

import static android.app.WindowConfiguration.ACTIVITY_TYPE_UNDEFINED;

import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN;

import static android.app.WindowConfiguration.WINDOWING_MODE_PINNED;

import static org.junit.Assert.assertEquals;

import static org.junit.Assert.assertNull;

import static org.junit.Assert.assertTrue;

import static org.mockito.Mockito.times;

import static org.mockito.Mockito.verify;

import static org.mockito.Mockito.doAnswer;

import static org.mockito.Mockito.mock;

import static org.mockito.ArgumentMatchers.any;

import android.app.ActivityManager;

import android.app.WaitResult;

import android.content.ComponentName;

import android.content.res.Configuration;

import android.graphics.Rect;

import android.hardware.display.DisplayManager;

import android.platform.test.annotations.Presubmit;

import android.support.test.filters.MediumTest;

import android.support.test.runner.AndroidJUnit4;

import android.util.SparseIntArray;

import org.junit.runner.RunWith;

import org.junit.Before;

import org.junit.Test;

import org.mockito.invocation.InvocationOnMock;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

        verify(stack, times(expectResumeTopActivity ? 1 : 0)).resumeTopActivityUncheckedLocked(

                null /* target */, null /* targetOptions */);

    }

    @Test

    public void testTopRunningActivityLockedWithNonExistentDisplay() throws Exception {

        // Create display that ActivityManagerService does not know about

        final int unknownDisplayId = 100;

        doAnswer((InvocationOnMock invocationOnMock) -> {

            final SparseIntArray displayIds = invocationOnMock.<SparseIntArray>getArgument(0);

            displayIds.put(0, unknownDisplayId);

            return null;

        }).when(mSupervisor.mWindowManager).getDisplaysInFocusOrder(any());

        mSupervisor.mFocusedStack = mock(ActivityStack.class);

        // Supervisor should skip over the non-existent display.

        assertEquals(null, mSupervisor.topRunningActivityLocked());

    }

}