Merge "[MediaProjection] Do not start layer mirroring without a surface" into sc-v2-dev am: 052c311bb2

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15684475

Change-Id: Iffd55a3ae6f1eb736cf6cd0f37a46abe904b1a31

core/java/com/android/internal/protolog/ProtoLogGroup.java

@@ -82,6 +82,8 @@ public enum ProtoLogGroup implements IProtoLogGroup {
             Consts.TAG_WM),
     WM_DEBUG_WINDOW_INSETS(Consts.ENABLE_DEBUG, Consts.ENABLE_LOG_TO_PROTO_DEBUG, false,
             Consts.TAG_WM),
+    WM_DEBUG_LAYER_MIRRORING(Consts.ENABLE_DEBUG, Consts.ENABLE_LOG_TO_PROTO_DEBUG, true,
+            Consts.TAG_WM),
     TEST_GROUP(true, true, false, "WindowManagerProtoLogTest");
 
     private final boolean mEnabled;

data/etc/services.core.protolog.json

@@ -211,6 +211,12 @@
       "group": "WM_DEBUG_SYNC_ENGINE",
       "at": "com\/android\/server\/wm\/BLASTSyncEngine.java"
     },
+    "-1898316768": {
+      "message": "Unable to retrieve window container to start layer mirroring for display %d",
+      "level": "VERBOSE",
+      "group": "WM_DEBUG_LAYER_MIRRORING",
+      "at": "com\/android\/server\/wm\/DisplayContent.java"
+    },
     "-1895337367": {
       "message": "Delete root task display=%d winMode=%d",
       "level": "VERBOSE",
@@ -1093,6 +1099,12 @@
       "group": "WM_ERROR",
       "at": "com\/android\/server\/wm\/WindowManagerService.java"
     },
+    "-904499590": {
+      "message": "Provided surface for layer mirroring on display %d is not present, so do not update the surface",
+      "level": "VERBOSE",
+      "group": "WM_DEBUG_LAYER_MIRRORING",
+      "at": "com\/android\/server\/wm\/DisplayContent.java"
+    },
     "-883738232": {
       "message": "Adding more than one toast window for UID at a time.",
       "level": "WARN",
@@ -1303,6 +1315,12 @@
       "group": "WM_DEBUG_ORIENTATION",
       "at": "com\/android\/server\/wm\/RootWindowContainer.java"
     },
+    "-663411559": {
+      "message": "Going ahead with updating layer mirroring for display %d to new bounds %s and\/or orientation %d.",
+      "level": "VERBOSE",
+      "group": "WM_DEBUG_LAYER_MIRRORING",
+      "at": "com\/android\/server\/wm\/DisplayContent.java"
+    },
     "-655104359": {
       "message": "Frontmost changed immersion: %s",
       "level": "DEBUG",
@@ -1561,6 +1579,12 @@
       "group": "WM_ERROR",
       "at": "com\/android\/server\/wm\/WindowManagerService.java"
     },
+    "-384564722": {
+      "message": "Unable to start layer mirroring for display %d since the surface is not available.",
+      "level": "VERBOSE",
+      "group": "WM_DEBUG_LAYER_MIRRORING",
+      "at": "com\/android\/server\/wm\/DisplayContent.java"
+    },
     "-381475323": {
       "message": "DisplayContent: boot is waiting for window of type %d to be drawn",
       "level": "DEBUG",
@@ -1633,6 +1657,12 @@
       "group": "WM_DEBUG_STATES",
       "at": "com\/android\/server\/wm\/TaskFragment.java"
     },
+    "-309399422": {
+      "message": "Display %d state is now (%d), so update layer mirroring?",
+      "level": "VERBOSE",
+      "group": "WM_DEBUG_LAYER_MIRRORING",
+      "at": "com\/android\/server\/wm\/DisplayContent.java"
+    },
     "-302468788": {
       "message": "Expected target rootTask=%s to be top most but found rootTask=%s",
       "level": "WARN",
@@ -1699,6 +1729,12 @@
       "group": "WM_DEBUG_WINDOW_MOVEMENT",
       "at": "com\/android\/server\/wm\/WindowManagerService.java"
     },
+    "-190034097": {
+      "message": "Unable to retrieve window container to update layer mirroring for display %d",
+      "level": "VERBOSE",
+      "group": "WM_DEBUG_LAYER_MIRRORING",
+      "at": "com\/android\/server\/wm\/DisplayContent.java"
+    },
     "-177040661": {
       "message": "Start rotation animation. customAnim=%s, mCurRotation=%s, mOriginalRotation=%s",
       "level": "DEBUG",
@@ -1795,6 +1831,12 @@
       "group": "WM_DEBUG_STATES",
       "at": "com\/android\/server\/wm\/TaskFragment.java"
     },
+    "-79877120": {
+      "message": "Display %d has content (%b) so disable layer mirroring",
+      "level": "VERBOSE",
+      "group": "WM_DEBUG_LAYER_MIRRORING",
+      "at": "com\/android\/server\/wm\/DisplayContent.java"
+    },
     "-70719599": {
       "message": "Unregister remote animations for organizer=%s uid=%d pid=%d",
       "level": "VERBOSE",
@@ -2347,6 +2389,12 @@
       "group": "WM_DEBUG_WINDOW_ORGANIZER",
       "at": "com\/android\/server\/wm\/DisplayAreaOrganizerController.java"
     },
+    "504397469": {
+      "message": "Unable to update layer mirroring for display %d to new bounds %s and\/or orientation %d, since the surface is not available.",
+      "level": "VERBOSE",
+      "group": "WM_DEBUG_LAYER_MIRRORING",
+      "at": "com\/android\/server\/wm\/DisplayContent.java"
+    },
     "508887531": {
       "message": "applyAnimation voice: anim=%s transit=%s isEntrance=%b Callers=%s",
       "level": "VERBOSE",
@@ -3103,6 +3151,12 @@
       "group": "WM_DEBUG_SCREEN_ON",
       "at": "com\/android\/server\/wm\/WindowManagerService.java"
     },
+    "1407569006": {
+      "message": "Display %d was already layer mirroring, so apply transformations if necessary",
+      "level": "VERBOSE",
+      "group": "WM_DEBUG_LAYER_MIRRORING",
+      "at": "com\/android\/server\/wm\/DisplayContent.java"
+    },
     "1417601133": {
       "message": "Enqueueing ADD_STARTING",
       "level": "VERBOSE",
@@ -3349,6 +3403,12 @@
       "group": "WM_DEBUG_CONFIGURATION",
       "at": "com\/android\/server\/wm\/ActivityRecord.java"
     },
+    "1687376052": {
+      "message": "Display %d has no content and is on, so start layer mirroring for state %d",
+      "level": "VERBOSE",
+      "group": "WM_DEBUG_LAYER_MIRRORING",
+      "at": "com\/android\/server\/wm\/DisplayContent.java"
+    },
     "1689989893": {
       "message": "SyncGroup %d: Set ready",
       "level": "VERBOSE",
@@ -3753,6 +3813,9 @@
     "WM_DEBUG_KEEP_SCREEN_ON": {
       "tag": "WindowManager"
     },
+    "WM_DEBUG_LAYER_MIRRORING": {
+      "tag": "WindowManager"
+    },
     "WM_DEBUG_LOCKTASK": {
       "tag": "WindowManager"
     },

services/core/java/com/android/server/display/VirtualDisplayAdapter.java

@@ -303,6 +303,9 @@ public class VirtualDisplayAdapter extends DisplayAdapter {
 
         @Override
         public Point getDisplaySurfaceDefaultSize() {
+            if (mSurface == null) {
+                return null;
+            }
             return mSurface.getDefaultSize();
         }
 

services/core/java/com/android/server/wm/DisplayContent.java

@@ -88,6 +88,7 @@ import static com.android.internal.protolog.ProtoLogGroup.WM_DEBUG_BOOT;
 import static com.android.internal.protolog.ProtoLogGroup.WM_DEBUG_FOCUS;
 import static com.android.internal.protolog.ProtoLogGroup.WM_DEBUG_FOCUS_LIGHT;
 import static com.android.internal.protolog.ProtoLogGroup.WM_DEBUG_IME;
+import static com.android.internal.protolog.ProtoLogGroup.WM_DEBUG_LAYER_MIRRORING;
 import static com.android.internal.protolog.ProtoLogGroup.WM_DEBUG_ORIENTATION;
 import static com.android.internal.protolog.ProtoLogGroup.WM_DEBUG_SCREEN_ON;
 import static com.android.internal.protolog.ProtoLogGroup.WM_SHOW_TRANSACTIONS;
@@ -305,7 +306,8 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
     @VisibleForTesting IBinder mTokenToMirror = null;
 
     /**
-     * The surface for mirroring the contents of this hierarchy.
+     * The surface for mirroring the contents of this hierarchy, or null if layer mirroring is
+     * temporarily disabled.
      */
     private SurfaceControl mMirroredSurface = null;
 
@@ -314,6 +316,11 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
      */
     private Rect mLastMirroredDisplayAreaBounds = null;
 
+    /**
+     * The last state of the display.
+     */
+    private int mLastDisplayState;
+
     // Contains all IME window containers. Note that the z-ordering of the IME windows will depend
     // on the IME target. We mainly have this container grouping so we can keep track of all the IME
     // window containers together and move them in-sync if/when needed. We use a subclass of
@@ -1142,10 +1149,6 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
         if (DEBUG_DISPLAY) Slog.v(TAG_WM, "Creating display=" + display);
 
         mWmService.mDisplayWindowSettings.applySettingsToDisplayLocked(this);
-
-        // Check if this DisplayContent is for a new VirtualDisplay, that should use layer mirroring
-        // to capture the contents of a DisplayArea.
-        startMirrorIfNeeded();
     }
 
     boolean isReady() {
@@ -2504,19 +2507,42 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
 
         // Update mirroring surface for MediaProjection, if this DisplayContent is being used
         // for layer mirroring.
-        if (mMirroredSurface != null) {
+        if (isCurrentlyMirroring() && mLastMirroredDisplayAreaBounds != null) {
-            // Retrieve the size of the DisplayArea to mirror, and continue with the update if the
+            // Mirroring has already begun, but update mirroring since the display is now on.
-            // bounds have changed.
             final WindowContainer wc = mWmService.mWindowContextListenerController.getContainer(
                     mTokenToMirror);
-            if (wc != null && mLastMirroredDisplayAreaBounds != null) {
+            if (wc == null) {
-                // Retrieve the size of the DisplayArea to mirror, and continue with the update
+                ProtoLog.v(WM_DEBUG_LAYER_MIRRORING,
-                // if the bounds or orientation has changed.
+                        "Unable to retrieve window container to update layer mirroring for "
-                final Rect displayAreaBounds = wc.getDisplayContent().getBounds();
+                                + "display %d",
-                int displayAreaOrientation = wc.getDisplayContent().getOrientation();
+                        mDisplayId);
-                if (!mLastMirroredDisplayAreaBounds.equals(displayAreaBounds)
+                return;
-                        || lastOrientation != displayAreaOrientation) {
+            }
-                    updateMirroredSurface(mWmService.mTransactionFactory.get(), displayAreaBounds);
+
+            ProtoLog.v(WM_DEBUG_LAYER_MIRRORING,
+                    "Display %d was already layer mirroring, so apply transformations if necessary",
+                    mDisplayId);
+            // Retrieve the size of the DisplayArea to mirror, and continue with the update
+            // if the bounds or orientation has changed.
+            final Rect displayAreaBounds = wc.getDisplayContent().getBounds();
+            int displayAreaOrientation = wc.getDisplayContent().getOrientation();
+            if (!mLastMirroredDisplayAreaBounds.equals(displayAreaBounds)
+                    || lastOrientation != displayAreaOrientation) {
+                Point surfaceSize = fetchSurfaceSizeIfPresent();
+                if (surfaceSize != null) {
+                    ProtoLog.v(WM_DEBUG_LAYER_MIRRORING,
+                            "Going ahead with updating layer mirroring for display %d to new "
+                                    + "bounds %s and/or orientation %d.",
+                            mDisplayId, displayAreaBounds, displayAreaOrientation);
+                    updateMirroredSurface(mWmService.mTransactionFactory.get(),
+                            displayAreaBounds, surfaceSize);
+                } else {
+                    // If the surface removed, do nothing. We will handle this via onDisplayChanged
+                    // (the display will be off if the surface is removed).
+                    ProtoLog.v(WM_DEBUG_LAYER_MIRRORING,
+                            "Unable to update layer mirroring for display %d to new bounds %s"
+                            + " and/or orientation %d, since the surface is not available.",
+                            mDisplayId, displayAreaBounds, displayAreaOrientation);
                 }
             }
         }
@@ -4405,6 +4431,7 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
                     mTmpApplySurfaceChangesTransactionState.preferMinimalPostProcessing,
                     true /* inTraversal, must call performTraversalInTrans... below */);
         }
+        // If the display now has content, or no longer has content, update layer mirroring.
         updateMirroring();
 
         final boolean wallpaperVisible = mWallpaperController.isWallpaperVisible();
@@ -5504,6 +5531,15 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
             } else if (displayState == Display.STATE_ON) {
                 mOffTokenAcquirer.release(mDisplayId);
             }
+            ProtoLog.v(WM_DEBUG_LAYER_MIRRORING,
+                    "Display %d state is now (%d), so update layer mirroring?",
+                    mDisplayId, displayState);
+            if (mLastDisplayState != displayState) {
+                // If state is on due to surface being added, then start layer mirroring.
+                // If state is off due to surface being removed, then stop layer mirroring.
+                updateMirroring();
+            }
+            mLastDisplayState = displayState;
         }
         mWmService.requestTraversal();
     }
@@ -5982,31 +6018,48 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
      * back to original MediaProjection approach.
      */
     private void startMirrorIfNeeded() {
-        // Only mirror if this display does not have its own content.
+        // Only mirror if this display does not have its own content, is not mirroring already,
-        if (mLastHasContent) {
+        // and if this display is on (it has a surface to write output to).
+        if (mLastHasContent || isCurrentlyMirroring() || mDisplay.getState() == Display.STATE_OFF) {
             return;
         }
+
         // Given the WindowToken of the DisplayArea to mirror, retrieve the associated
         // SurfaceControl.
         IBinder tokenToMirror = mWmService.mDisplayManagerInternal.getWindowTokenClientToMirror(
                 mDisplayId);
-
         if (tokenToMirror == null) {
             // This DisplayContent instance is not involved in layer mirroring. If the display
             // has been created for capturing, fall back to prior MediaProjection approach.
             return;
         }
+
         final WindowContainer wc = mWmService.mWindowContextListenerController.getContainer(
                 tokenToMirror);
         if (wc == null) {
             // Un-set the window token to mirror for this VirtualDisplay, to fall back to the
             // original MediaProjection approach.
             mWmService.mDisplayManagerInternal.setWindowTokenClientToMirror(mDisplayId, null);
+            ProtoLog.v(WM_DEBUG_LAYER_MIRRORING,
+                    "Unable to retrieve window container to start layer mirroring for display %d",
+                    mDisplayId);
             return;
         }
-        SurfaceControl sc = wc.getDisplayContent().getSurfaceControl();
+
+        Point surfaceSize = fetchSurfaceSizeIfPresent();
+        if (surfaceSize == null) {
+            ProtoLog.v(WM_DEBUG_LAYER_MIRRORING,
+                    "Unable to start layer mirroring for display %d since the surface is not "
+                            + "available.",
+                    mDisplayId);
+            return;
+        }
+        ProtoLog.v(WM_DEBUG_LAYER_MIRRORING,
+                "Display %d has no content and is on, so start layer mirroring for state %d",
+                mDisplayId, mDisplay.getState());
 
         // Create a mirrored hierarchy for the SurfaceControl of the DisplayArea to capture.
+        SurfaceControl sc = wc.getDisplayContent().getSurfaceControl();
         mMirroredSurface = SurfaceControl.mirrorSurface(sc);
         SurfaceControl.Transaction transaction = mWmService.mTransactionFactory.get()
                 // Set the mMirroredSurface's parent to the root SurfaceControl for this
@@ -6019,7 +6072,7 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
                 // VirtualDisplay will show up as part of the mirrored content.
                 .reparent(mWindowingLayer, null);
         // Retrieve the size of the DisplayArea to mirror.
-        updateMirroredSurface(transaction, wc.getDisplayContent().getBounds());
+        updateMirroredSurface(transaction, wc.getDisplayContent().getBounds(), surfaceSize);
         mTokenToMirror = tokenToMirror;
 
         // No need to clean up. In SurfaceFlinger, parents hold references to their children. The
@@ -6029,11 +6082,18 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
     }
 
     /**
-     * Start or stop mirroring if this DisplayContent now has content, or no longer has content.
+     * Start mirroring if this DisplayContent no longer has content. Stop mirroring if it now
+     * has content or the display is not on.
      */
     private void updateMirroring() {
-        if (mLastHasContent && mMirroredSurface != null) {
+        if (isCurrentlyMirroring() && (mLastHasContent
-            // Display now has content, so stop mirroring to it.
+                || mDisplay.getState() == Display.STATE_OFF)) {
+            ProtoLog.v(WM_DEBUG_LAYER_MIRRORING,
+                    "Display %d has content (%b) so disable layer mirroring", mDisplayId,
+                    mLastHasContent);
+            // If the display is not on and it is a virtual display, then it no longer has an
+            // associated surface to write output to.
+            // If the display now has content, stop mirroring to it.
             mWmService.mTransactionFactory.get()
                     // Remove the reference to mMirroredSurface, to clean up associated memory.
                     .remove(mMirroredSurface)
@@ -6044,8 +6104,9 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
             // Stop mirroring by destroying the reference to the mirrored layer.
             mMirroredSurface = null;
             // Do not un-set the token, in case content is removed and mirroring should begin again.
-        } else if (!mLastHasContent && mMirroredSurface == null) {
+        } else {
-            // Display no longer has content, so start mirroring to it.
+            // Display no longer has content, or now has a surface to write to, so try to start
+            // mirroring to it.
             startMirrorIfNeeded();
         }
     }
@@ -6054,21 +6115,15 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
      * Apply transformations to the mirrored surface to ensure the captured contents are scaled to
      * fit and centred in the output surface.
      *
-     * @param transaction            the transaction to include transformations of mMirroredSurface
+     * @param transaction       the transaction to include transformations of mMirroredSurface
-     *                               to. Transaction is not applied before returning.
+     *                          to. Transaction is not applied before returning.
-     * @param displayAreaBounds      bounds of the DisplayArea to mirror to the surface provided by
+     * @param displayAreaBounds bounds of the DisplayArea to mirror to the surface provided by
-     *                               the app.
+     *                          the app.
+     * @param surfaceSize       the default size of the surface to write the display area content to
      */
     @VisibleForTesting
     void updateMirroredSurface(SurfaceControl.Transaction transaction,
-            Rect displayAreaBounds) {
+            Rect displayAreaBounds, Point surfaceSize) {
-        // Retrieve the default size of the surface the app provided to
-        // MediaProjection#createVirtualDisplay. Note the app is the consumer of the surface,
-        // since it reads out buffers from the surface, and SurfaceFlinger is the producer since
-        // it writes the mirrored layers to the buffers.
-        final Point surfaceSize = mWmService.mDisplayManagerInternal.getDisplaySurfaceDefaultSize(
-                mDisplayId);
-
         // Calculate the scale to apply to the root mirror SurfaceControl to fit the size of the
         // output surface.
         float scaleX = surfaceSize.x / (float) displayAreaBounds.width();
@@ -6103,6 +6158,36 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
         mLastMirroredDisplayAreaBounds = new Rect(displayAreaBounds);
     }
 
+    /**
+     * Returns a non-null {@link Point} if the surface is present, or null otherwise
+     */
+    Point fetchSurfaceSizeIfPresent() {
+        // Retrieve the default size of the surface the app provided to
+        // MediaProjection#createVirtualDisplay. Note the app is the consumer of the surface,
+        // since it reads out buffers from the surface, and SurfaceFlinger is the producer since
+        // it writes the mirrored layers to the buffers.
+        Point surfaceSize = mWmService.mDisplayManagerInternal.getDisplaySurfaceDefaultSize(
+                mDisplayId);
+        if (surfaceSize == null) {
+            // Layer mirroring started with a null surface, so do not apply any transformations yet.
+            // State of virtual display will change to 'ON' when the surface is set.
+            // will get event DISPLAY_DEVICE_EVENT_CHANGED
+            ProtoLog.v(WM_DEBUG_LAYER_MIRRORING,
+                    "Provided surface for layer mirroring on display %d is not present, so do not"
+                            + " update the surface",
+                    mDisplayId);
+            return null;
+        }
+        return surfaceSize;
+    }
+
+    /**
+     * Returns {@code true} if this DisplayContent is currently layer mirroring.
+     */
+    boolean isCurrentlyMirroring() {
+        return mTokenToMirror != null && mMirroredSurface != null;
+    }
+
     /** The entry for proceeding to handle {@link #mFixedRotationLaunchingApp}. */
     class FixedRotationTransitionListener extends WindowManagerInternal.AppTransitionListener {
 

services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java

@@ -25,6 +25,7 @@ import static android.content.pm.ActivityInfo.FLAG_SHOW_WHEN_LOCKED;
 import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE;
 import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_PORTRAIT;
 import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
+import static android.hardware.display.DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR;
 import static android.os.Build.VERSION_CODES.P;
 import static android.os.Build.VERSION_CODES.Q;
 import static android.view.Display.DEFAULT_DISPLAY;
@@ -111,6 +112,7 @@ import android.graphics.Insets;
 import android.graphics.Point;
 import android.graphics.Rect;
 import android.graphics.Region;
+import android.hardware.display.VirtualDisplay;
 import android.metrics.LogMaker;
 import android.os.Binder;
 import android.os.IBinder;
@@ -2292,7 +2294,7 @@ public class DisplayContentTests extends WindowTestsBase {
         float yScale = 2f;
         Rect displayAreaBounds = new Rect(0, 0, Math.round(surfaceSize.x * xScale),
                 Math.round(surfaceSize.y * yScale));
-        virtualDisplay.updateMirroredSurface(mTransaction, displayAreaBounds);
+        virtualDisplay.updateMirroredSurface(mTransaction, displayAreaBounds, surfaceSize);
 
         // THEN content in the captured DisplayArea is scaled to fit the surface size.
         verify(mTransaction, atLeastOnce()).setMatrix(mirroredSurface, 1.0f / yScale, 0, 0,
@@ -2305,6 +2307,72 @@ public class DisplayContentTests extends WindowTestsBase {
         mockSession.finishMocking();
     }
 
+    @Test
+    public void testVirtualDisplayContent_withoutSurface() {
+        MockitoSession mockSession = mockitoSession()
+                .initMocks(this)
+                .spyStatic(SurfaceControl.class)
+                .strictness(Strictness.LENIENT)
+                .startMocking();
+
+        // GIVEN MediaProjection has already initialized the WindowToken of the DisplayArea to
+        // mirror.
+        setUpDefaultTaskDisplayAreaWindowToken();
+
+        // GIVEN SurfaceControl can successfully mirror the provided surface.
+        Point surfaceSize = new Point(
+                mDefaultDisplay.getDefaultTaskDisplayArea().getBounds().width(),
+                mDefaultDisplay.getDefaultTaskDisplayArea().getBounds().height());
+        surfaceControlMirrors(surfaceSize);
+
+        // GIVEN a new VirtualDisplay with an associated surface.
+        final VirtualDisplay display = createVirtualDisplay(surfaceSize, null /* surface */);
+        final int displayId = display.getDisplay().getDisplayId();
+        mWm.mRoot.onDisplayAdded(displayId);
+
+        // WHEN getting the DisplayContent for the new virtual display.
+        DisplayContent actualDC = mWm.mRoot.getDisplayContent(displayId);
+
+        // THEN mirroring is not started, since a null surface indicates the VirtualDisplay is off.
+        assertThat(actualDC.mTokenToMirror).isNull();
+
+        display.release();
+        mockSession.finishMocking();
+    }
+
+    @Test
+    public void testVirtualDisplayContent_withSurface() {
+        MockitoSession mockSession = mockitoSession()
+                .initMocks(this)
+                .spyStatic(SurfaceControl.class)
+                .strictness(Strictness.LENIENT)
+                .startMocking();
+
+        // GIVEN MediaProjection has already initialized the WindowToken of the DisplayArea to
+        // mirror.
+        final IBinder tokenToMirror = setUpDefaultTaskDisplayAreaWindowToken();
+
+        // GIVEN SurfaceControl can successfully mirror the provided surface.
+        Point surfaceSize = new Point(
+                mDefaultDisplay.getDefaultTaskDisplayArea().getBounds().width(),
+                mDefaultDisplay.getDefaultTaskDisplayArea().getBounds().height());
+        surfaceControlMirrors(surfaceSize);
+
+        // GIVEN a new VirtualDisplay with an associated surface.
+        final VirtualDisplay display = createVirtualDisplay(surfaceSize, new Surface());
+        final int displayId = display.getDisplay().getDisplayId();
+        mWm.mRoot.onDisplayAdded(displayId);
+
+        // WHEN getting the DisplayContent for the new virtual display.
+        DisplayContent actualDC = mWm.mRoot.getDisplayContent(displayId);
+
+        // THEN mirroring is initiated for the default display's DisplayArea.
+        assertThat(actualDC.mTokenToMirror).isEqualTo(tokenToMirror);
+
+        display.release();
+        mockSession.finishMocking();
+    }
+
     private class TestToken extends Binder {
     }
 
@@ -2342,6 +2410,11 @@ public class DisplayContentTests extends WindowTestsBase {
         return mirroredSurface;
     }
 
+    private VirtualDisplay createVirtualDisplay(Point size, Surface surface) {
+        return mWm.mDisplayManager.createVirtualDisplay("VirtualDisplay", size.x, size.y,
+                DisplayMetrics.DENSITY_140, surface, VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR);
+    }
+
     private void removeRootTaskTests(Runnable runnable) {
         final TaskDisplayArea taskDisplayArea = mRootWindowContainer.getDefaultTaskDisplayArea();
         final Task rootTask1 = taskDisplayArea.createRootTask(WINDOWING_MODE_FULLSCREEN,