diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 5cf7a5f..326da3a 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -68,6 +68,7 @@
         "android/gui/FocusRequest.aidl",
         "android/gui/InputApplicationInfo.aidl",
         "android/gui/IWindowInfosListener.aidl",
+        "android/gui/IWindowInfosReportedListener.aidl",
         "android/gui/WindowInfo.aidl",
         "WindowInfo.cpp",
     ],
diff --git a/libs/gui/WindowInfosListenerReporter.cpp b/libs/gui/WindowInfosListenerReporter.cpp
index 834e2b8..c00a438 100644
--- a/libs/gui/WindowInfosListenerReporter.cpp
+++ b/libs/gui/WindowInfosListenerReporter.cpp
@@ -19,6 +19,7 @@
 
 namespace android {
 
+using gui::IWindowInfosReportedListener;
 using gui::WindowInfo;
 using gui::WindowInfosListener;
 
@@ -64,7 +65,8 @@
 }
 
 binder::Status WindowInfosListenerReporter::onWindowInfosChanged(
-        const std::vector<WindowInfo>& windowInfos) {
+        const std::vector<WindowInfo>& windowInfos,
+        const sp<IWindowInfosReportedListener>& windowInfosReportedListener) {
     std::unordered_set<sp<WindowInfosListener>, ISurfaceComposer::SpHash<WindowInfosListener>>
             windowInfosListeners;
 
@@ -79,6 +81,10 @@
         listener->onWindowInfosChanged(windowInfos);
     }
 
+    if (windowInfosReportedListener) {
+        windowInfosReportedListener->onWindowInfosReported();
+    }
+
     return binder::Status::ok();
 }
 
diff --git a/libs/gui/android/gui/IWindowInfosListener.aidl b/libs/gui/android/gui/IWindowInfosListener.aidl
index 500d928..d4553ca 100644
--- a/libs/gui/android/gui/IWindowInfosListener.aidl
+++ b/libs/gui/android/gui/IWindowInfosListener.aidl
@@ -16,10 +16,11 @@
 
 package android.gui;
 
+import android.gui.IWindowInfosReportedListener;
 import android.gui.WindowInfo;
 
 /** @hide */
 oneway interface IWindowInfosListener
 {
-    void onWindowInfosChanged(in WindowInfo[] windowInfos);
+    void onWindowInfosChanged(in WindowInfo[] windowInfos, in @nullable IWindowInfosReportedListener windowInfosReportedListener);
 }
diff --git a/libs/gui/android/gui/IWindowInfosReportedListener.aidl b/libs/gui/android/gui/IWindowInfosReportedListener.aidl
new file mode 100644
index 0000000..0e4cce6
--- /dev/null
+++ b/libs/gui/android/gui/IWindowInfosReportedListener.aidl
@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) 2020, 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 android.gui;
+
+/** @hide */
+oneway interface IWindowInfosReportedListener
+{
+    void onWindowInfosReported();
+}
diff --git a/libs/gui/include/gui/WindowInfosListenerReporter.h b/libs/gui/include/gui/WindowInfosListenerReporter.h
index 3e346de..7cb96e0 100644
--- a/libs/gui/include/gui/WindowInfosListenerReporter.h
+++ b/libs/gui/include/gui/WindowInfosListenerReporter.h
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <android/gui/BnWindowInfosListener.h>
+#include <android/gui/IWindowInfosReportedListener.h>
 #include <binder/IBinder.h>
 #include <gui/ISurfaceComposer.h>
 #include <gui/WindowInfosListener.h>
@@ -29,8 +30,8 @@
 class WindowInfosListenerReporter : public gui::BnWindowInfosListener {
 public:
     static sp<WindowInfosListenerReporter> getInstance();
-
-    binder::Status onWindowInfosChanged(const std::vector<gui::WindowInfo>& windowInfos) override;
+    binder::Status onWindowInfosChanged(const std::vector<gui::WindowInfo>& windowInfos,
+                                        const sp<gui::IWindowInfosReportedListener>&) override;
 
     status_t addWindowInfosListener(const sp<gui::WindowInfosListener>& windowInfosListener,
                                     const sp<ISurfaceComposer>&);