diff --git a/api/test-current.txt b/api/test-current.txt
index 1981d68..ba497d4 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -17,6 +17,10 @@
     field public static final String WRITE_OBB = "android.permission.WRITE_OBB";
   }
 
+  public static final class R.bool {
+    field public static final int config_perDisplayFocusEnabled = 17891332; // 0x1110004
+  }
+
   public static final class R.string {
     field public static final int config_defaultAssistant = 17039393; // 0x1040021
     field public static final int config_defaultDialer = 17039395; // 0x1040023
@@ -48,6 +52,7 @@
     method public long getTotalRam();
     method @RequiresPermission(android.Manifest.permission.PACKAGE_USAGE_STATS) public int getUidImportance(int);
     method @RequiresPermission(android.Manifest.permission.PACKAGE_USAGE_STATS) public void removeOnUidImportanceListener(android.app.ActivityManager.OnUidImportanceListener);
+    method public static void resumeAppSwitches() throws android.os.RemoteException;
     method @RequiresPermission(android.Manifest.permission.CHANGE_CONFIGURATION) public void scheduleApplicationInfoChanged(java.util.List<java.lang.String>, int);
   }
 
@@ -94,6 +99,31 @@
     field public static final int SPLIT_SCREEN_CREATE_MODE_TOP_OR_LEFT = 0; // 0x0
   }
 
+  public class ActivityView extends android.view.ViewGroup {
+    ctor public ActivityView(android.content.Context);
+    ctor public ActivityView(android.content.Context, android.util.AttributeSet);
+    ctor public ActivityView(android.content.Context, android.util.AttributeSet, int);
+    ctor public ActivityView(android.content.Context, android.util.AttributeSet, int, boolean);
+    method public void onLayout(boolean, int, int, int, int);
+    method public void onLocationChanged();
+    method public void performBackPress();
+    method public void release();
+    method public void setCallback(android.app.ActivityView.StateCallback);
+    method public void setForwardedInsets(android.graphics.Insets);
+    method public void startActivity(@NonNull android.content.Intent);
+    method public void startActivity(@NonNull android.content.Intent, android.os.UserHandle);
+    method public void startActivity(@NonNull android.app.PendingIntent);
+  }
+
+  public abstract static class ActivityView.StateCallback {
+    ctor public ActivityView.StateCallback();
+    method public abstract void onActivityViewDestroyed(android.app.ActivityView);
+    method public abstract void onActivityViewReady(android.app.ActivityView);
+    method public void onTaskCreated(int, android.content.ComponentName);
+    method public void onTaskMovedToFront(int);
+    method public void onTaskRemovalStarted(int);
+  }
+
   public class AppDetailsActivity extends android.app.Activity {
     ctor public AppDetailsActivity();
   }
@@ -518,12 +548,17 @@
 
   public abstract class Context {
     method public android.content.Context createPackageContextAsUser(String, int, android.os.UserHandle) throws android.content.pm.PackageManager.NameNotFoundException;
+    method public abstract android.view.Display getDisplay();
     method public android.os.UserHandle getUser();
     method public int getUserId();
     method public void setAutofillOptions(@Nullable android.content.AutofillOptions);
     method public void setContentCaptureOptions(@Nullable android.content.ContentCaptureOptions);
   }
 
+  public class ContextWrapper extends android.content.Context {
+    method public android.view.Display getDisplay();
+  }
+
 }
 
 package android.content.pm {
@@ -969,6 +1004,50 @@
 
 }
 
+package android.metrics {
+
+  public class LogMaker {
+    ctor public LogMaker(int);
+    ctor public LogMaker(Object[]);
+    method public android.metrics.LogMaker addTaggedData(int, Object);
+    method public android.metrics.LogMaker clearCategory();
+    method public android.metrics.LogMaker clearPackageName();
+    method public android.metrics.LogMaker clearSubtype();
+    method public android.metrics.LogMaker clearTaggedData(int);
+    method public android.metrics.LogMaker clearType();
+    method public void deserialize(Object[]);
+    method public int getCategory();
+    method public long getCounterBucket();
+    method public String getCounterName();
+    method public int getCounterValue();
+    method public String getPackageName();
+    method public int getProcessId();
+    method public int getSubtype();
+    method public Object getTaggedData(int);
+    method public long getTimestamp();
+    method public int getType();
+    method public int getUid();
+    method public boolean isLongCounterBucket();
+    method public boolean isSubsetOf(android.metrics.LogMaker);
+    method public boolean isValidValue(Object);
+    method public Object[] serialize();
+    method public android.metrics.LogMaker setCategory(int);
+    method public android.metrics.LogMaker setPackageName(String);
+    method public android.metrics.LogMaker setSubtype(int);
+    method public android.metrics.LogMaker setType(int);
+  }
+
+  public class MetricsReader {
+    ctor public MetricsReader();
+    method public void checkpoint();
+    method public boolean hasNext();
+    method public android.metrics.LogMaker next();
+    method public void read(long);
+    method public void reset();
+  }
+
+}
+
 package android.net {
 
   public class CaptivePortal implements android.os.Parcelable {
@@ -1313,6 +1392,7 @@
 
   public class Build {
     method public static boolean is64BitAbi(String);
+    field public static final boolean IS_EMULATOR;
   }
 
   public static class Build.VERSION {
@@ -1893,6 +1973,7 @@
     field public static final String LOCATION_GLOBAL_KILL_SWITCH = "location_global_kill_switch";
     field public static final String LOW_POWER_MODE = "low_power";
     field public static final String LOW_POWER_MODE_STICKY = "low_power_sticky";
+    field public static final String OVERLAY_DISPLAY_DEVICES = "overlay_display_devices";
     field public static final String SMS_ACCESS_RESTRICTION_ENABLED = "sms_access_restriction_enabled";
     field public static final String USE_OPEN_WIFI_PACKAGE = "use_open_wifi_package";
   }
@@ -1911,6 +1992,7 @@
     field public static final String CONTENT_CAPTURE_ENABLED = "content_capture_enabled";
     field public static final String DISABLED_PRINT_SERVICES = "disabled_print_services";
     field @Deprecated public static final String ENABLED_NOTIFICATION_POLICY_ACCESS_PACKAGES = "enabled_notification_policy_access_packages";
+    field public static final String ENABLED_VR_LISTENERS = "enabled_vr_listeners";
     field public static final String LOCATION_ACCESS_CHECK_DELAY_MILLIS = "location_access_check_delay_millis";
     field public static final String LOCATION_ACCESS_CHECK_INTERVAL_MILLIS = "location_access_check_interval_millis";
     field public static final String NOTIFICATION_BADGING = "notification_badging";
@@ -2391,6 +2473,10 @@
     method public E valueAtUnchecked(int);
   }
 
+  public class TimeUtils {
+    method public static String formatDuration(long);
+  }
+
 }
 
 package android.util.proto {
@@ -2612,6 +2698,10 @@
     field public static final int CALLBACK_ANIMATION = 1; // 0x1
   }
 
+  public final class Display {
+    method public boolean supportsSystemDecorations();
+  }
+
   public class FocusFinder {
     method public static void sort(android.view.View[], int, int, android.view.ViewGroup, boolean);
   }
diff --git a/config/hiddenapi-greylist.txt b/config/hiddenapi-greylist.txt
index 7f7972a..2abb631 100644
--- a/config/hiddenapi-greylist.txt
+++ b/config/hiddenapi-greylist.txt
@@ -688,7 +688,6 @@
 Landroid/os/Build;->getLong(Ljava/lang/String;)J
 Landroid/os/Build;->getString(Ljava/lang/String;)Ljava/lang/String;
 Landroid/os/Build;->IS_DEBUGGABLE:Z
-Landroid/os/Build;->IS_EMULATOR:Z
 Landroid/os/Bundle;->filterValues()Landroid/os/Bundle;
 Landroid/os/Bundle;->forPair(Ljava/lang/String;Ljava/lang/String;)Landroid/os/Bundle;
 Landroid/os/Bundle;->getIBinder(Ljava/lang/String;)Landroid/os/IBinder;
diff --git a/core/java/android/app/ActivityManager.java b/core/java/android/app/ActivityManager.java
index 5d4f988..ee7288f 100644
--- a/core/java/android/app/ActivityManager.java
+++ b/core/java/android/app/ActivityManager.java
@@ -3925,6 +3925,14 @@
     /**
      * @hide
      */
+    @TestApi
+    public static void resumeAppSwitches() throws RemoteException {
+        getService().resumeAppSwitches();
+    }
+
+    /**
+     * @hide
+     */
     public static void noteWakeupAlarm(PendingIntent ps, WorkSource workSource, int sourceUid,
             String sourcePkg, String tag) {
         try {
diff --git a/core/java/android/app/ActivityView.java b/core/java/android/app/ActivityView.java
index a4b763d..2ef0856 100644
--- a/core/java/android/app/ActivityView.java
+++ b/core/java/android/app/ActivityView.java
@@ -21,7 +21,7 @@
 import static android.hardware.display.DisplayManager.VIRTUAL_DISPLAY_FLAG_PUBLIC;
 
 import android.annotation.NonNull;
-import android.annotation.UnsupportedAppUsage;
+import android.annotation.TestApi;
 import android.app.ActivityManager.StackInfo;
 import android.content.ComponentName;
 import android.content.Context;
@@ -59,6 +59,7 @@
  * on VirtualDisplays.
  * @hide
  */
+@TestApi
 public class ActivityView extends ViewGroup {
 
     private static final String DISPLAY_NAME = "ActivityViewVirtualDisplay";
@@ -92,7 +93,6 @@
 
     private Insets mForwardedInsets;
 
-    @UnsupportedAppUsage
     public ActivityView(Context context) {
         this(context, null /* attrs */);
     }
@@ -151,7 +151,7 @@
          * Called when a task is moved to the front of the stack inside the container.
          * This is a filtered version of {@link TaskStackListener}
          */
-        public void onTaskMovedToFront(ActivityManager.StackInfo stackInfo) { }
+        public void onTaskMovedToFront(int taskId) { }
 
         /**
          * Called when a task is about to be removed from the stack inside the container.
@@ -195,7 +195,6 @@
      * @see StateCallback
      * @see #startActivity(PendingIntent)
      */
-    @UnsupportedAppUsage
     public void startActivity(@NonNull Intent intent) {
         final ActivityOptions options = prepareActivityOptions();
         getContext().startActivity(intent, options.toBundle());
@@ -238,7 +237,6 @@
      * @see StateCallback
      * @see #startActivity(Intent)
      */
-    @UnsupportedAppUsage
     public void startActivity(@NonNull PendingIntent pendingIntent) {
         final ActivityOptions options = prepareActivityOptions();
         try {
@@ -272,7 +270,6 @@
      *
      * @see StateCallback
      */
-    @UnsupportedAppUsage
     public void release() {
         if (mVirtualDisplay == null) {
             throw new IllegalStateException(
@@ -556,7 +553,7 @@
             // notifying the callback
             if (stackInfo != null
                     && taskInfo.taskId == stackInfo.taskIds[stackInfo.taskIds.length - 1]) {
-                mActivityViewCallback.onTaskMovedToFront(stackInfo);
+                mActivityViewCallback.onTaskMovedToFront(taskInfo.taskId);
             }
         }
 
diff --git a/core/java/android/app/ContextImpl.java b/core/java/android/app/ContextImpl.java
index b792ad2..b607f9a 100644
--- a/core/java/android/app/ContextImpl.java
+++ b/core/java/android/app/ContextImpl.java
@@ -19,6 +19,7 @@
 import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.annotation.TestApi;
 import android.annotation.UnsupportedAppUsage;
 import android.content.AutofillOptions;
 import android.content.BroadcastReceiver;
@@ -2283,8 +2284,8 @@
         return (mFlags & Context.CONTEXT_IGNORE_SECURITY) != 0;
     }
 
+    @TestApi
     @Override
-    @UnsupportedAppUsage
     public Display getDisplay() {
         if (mDisplay == null) {
             return mResourcesManager.getAdjustedDisplay(Display.DEFAULT_DISPLAY,
diff --git a/core/java/android/content/Context.java b/core/java/android/content/Context.java
index 1f3a000..29added 100644
--- a/core/java/android/content/Context.java
+++ b/core/java/android/content/Context.java
@@ -5241,9 +5241,10 @@
     public abstract DisplayAdjustments getDisplayAdjustments(int displayId);
 
     /**
+     * @return Returns the {@link Display} object this context is associated with.
      * @hide
      */
-    @UnsupportedAppUsage
+    @TestApi
     public abstract Display getDisplay();
 
     /**
diff --git a/core/java/android/content/ContextWrapper.java b/core/java/android/content/ContextWrapper.java
index fac3266..40559d3 100644
--- a/core/java/android/content/ContextWrapper.java
+++ b/core/java/android/content/ContextWrapper.java
@@ -919,11 +919,9 @@
         return mBase.getDisplayAdjustments(displayId);
     }
 
-    /**
-     * @hide
-     */
+    /** @hide */
+    @TestApi
     @Override
-    @UnsupportedAppUsage
     public Display getDisplay() {
         return mBase.getDisplay();
     }
diff --git a/core/java/android/metrics/LogMaker.java b/core/java/android/metrics/LogMaker.java
index 19848ee..5496e17 100644
--- a/core/java/android/metrics/LogMaker.java
+++ b/core/java/android/metrics/LogMaker.java
@@ -16,6 +16,7 @@
 package android.metrics;
 
 import android.annotation.SystemApi;
+import android.annotation.TestApi;
 import android.content.ComponentName;
 import android.util.Log;
 import android.util.SparseArray;
@@ -31,6 +32,7 @@
  * @hide
  */
 @SystemApi
+@TestApi
 public class LogMaker {
     private static final String TAG = "LogBuilder";
 
diff --git a/core/java/android/metrics/MetricsReader.java b/core/java/android/metrics/MetricsReader.java
index 5f356ca..27f9a5d 100644
--- a/core/java/android/metrics/MetricsReader.java
+++ b/core/java/android/metrics/MetricsReader.java
@@ -16,6 +16,7 @@
 package android.metrics;
 
 import android.annotation.SystemApi;
+import android.annotation.TestApi;
 import android.util.EventLog;
 
 import com.android.internal.annotations.VisibleForTesting;
@@ -35,6 +36,7 @@
  * @hide
  */
 @SystemApi
+@TestApi
 public class MetricsReader {
     private Queue<LogMaker> mPendingQueue = new LinkedList<>();
     private Queue<LogMaker> mSeenQueue = new LinkedList<>();
diff --git a/core/java/android/os/Build.java b/core/java/android/os/Build.java
index 83a7654..0425c62 100755
--- a/core/java/android/os/Build.java
+++ b/core/java/android/os/Build.java
@@ -107,6 +107,7 @@
      * Whether this build was for an emulator device.
      * @hide
      */
+    @TestApi
     public static final boolean IS_EMULATOR = getString("ro.kernel.qemu").equals("1");
 
     /**
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 77e896e..1530626 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -8131,6 +8131,7 @@
          *
          * @hide
          */
+        @TestApi
         public static final String ENABLED_VR_LISTENERS = "enabled_vr_listeners";
 
         private static final Validator ENABLED_VR_LISTENERS_VALIDATOR =
@@ -10780,6 +10781,7 @@
         *
         * @hide
         */
+       @TestApi
        public static final String OVERLAY_DISPLAY_DEVICES = "overlay_display_devices";
 
         /**
diff --git a/core/java/android/util/TimeUtils.java b/core/java/android/util/TimeUtils.java
index e4c8eeb..f8b38e9 100644
--- a/core/java/android/util/TimeUtils.java
+++ b/core/java/android/util/TimeUtils.java
@@ -18,6 +18,7 @@
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.annotation.TestApi;
 import android.annotation.UnsupportedAppUsage;
 import android.os.Build;
 import android.os.SystemClock;
@@ -302,6 +303,7 @@
     }
 
     /** @hide Just for debugging; not internationalized. */
+    @TestApi
     public static String formatDuration(long duration) {
         synchronized (sFormatSync) {
             int len = formatDurationLocked(duration, 0);
diff --git a/core/java/android/view/Display.java b/core/java/android/view/Display.java
index cb5100a..94a9a1c 100644
--- a/core/java/android/view/Display.java
+++ b/core/java/android/view/Display.java
@@ -21,6 +21,7 @@
 import android.annotation.IntDef;
 import android.annotation.Nullable;
 import android.annotation.RequiresPermission;
+import android.annotation.TestApi;
 import android.annotation.UnsupportedAppUsage;
 import android.app.KeyguardManager;
 import android.content.res.CompatibilityInfo;
@@ -911,6 +912,7 @@
      * @see #FLAG_SHOULD_SHOW_SYSTEM_DECORATIONS
      * @hide
      */
+    @TestApi
     // TODO (b/114338689): Remove the method and use IWindowManager#shouldShowSystemDecors
     public boolean supportsSystemDecorations() {
         return (mDisplayInfo.flags & FLAG_SHOULD_SHOW_SYSTEM_DECORATIONS) != 0;
diff --git a/core/res/res/values/public.xml b/core/res/res/values/public.xml
index e1ce2f6..5a3c536 100644
--- a/core/res/res/values/public.xml
+++ b/core/res/res/values/public.xml
@@ -2998,6 +2998,8 @@
       <public name="config_showDefaultEmergency" />
       <!-- @hide @SystemApi -->
       <public name="config_showDefaultHome" />
+      <!-- @hide @TestApi -->
+      <public name="config_perDisplayFocusEnabled" />
     </public-group>
 
     <public-group type="dimen" first-id="0x01050007">
diff --git a/proto/Android.bp b/proto/Android.bp
index 817a54d..7f826b3 100644
--- a/proto/Android.bp
+++ b/proto/Android.bp
@@ -6,6 +6,7 @@
     },
     srcs: ["src/**/*.proto"],
     no_framework_libs: true,
+    sdk_version: "9",
     // Pin java_version until jarjar is certified to support later versions. http://b/72703434
     java_version: "1.8",
     target: {
diff --git a/test-mock/api/test-current.txt b/test-mock/api/test-current.txt
index 0cb8f22..6765316 100644
--- a/test-mock/api/test-current.txt
+++ b/test-mock/api/test-current.txt
@@ -1,6 +1,10 @@
 // Signature format: 2.0
 package android.test.mock {
 
+  public class MockContext extends android.content.Context {
+    method public android.view.Display getDisplay();
+  }
+
   @Deprecated public class MockPackageManager extends android.content.pm.PackageManager {
     method public boolean arePermissionsIndividuallyControlled();
     method public String getDefaultBrowserPackageNameAsUser(int);