Don't set override display info for ActivityView

ActivityView content should never be letter- or pillar-boxed
and it doesn't have overscan areas, so we can skip setting
display override info for a virtual display that backs it.

Bug: 72220802
Test: Manually resize with ActivityView demo app
Change-Id: I211449eaea50ec5d3214d63e7eb93a1d2ed2c0fd
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index c35c05d..e2e1690 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -305,6 +305,11 @@
     int pendingLayoutChanges;
     // TODO(multi-display): remove some of the usages.
     boolean isDefaultDisplay;
+    /**
+     * Flag indicating whether WindowManager should override info for this display in
+     * DisplayManager.
+     */
+    boolean mShouldOverrideDisplayConfiguration = true;
 
     /** Window tokens that are in the process of exiting, but still on screen for animations. */
     final ArrayList<WindowToken> mExitingTokens = new ArrayList<>();
@@ -1177,8 +1182,14 @@
             mDisplayInfo.flags &= ~Display.FLAG_SCALING_DISABLED;
         }
 
+        // We usually set the override info in DisplayManager so that we get consistent display
+        // metrics values when displays are changing and don't send out new values until WM is aware
+        // of them. However, we don't do this for displays that serve as containers for ActivityView
+        // because we don't want letter-/pillar-boxing during resize.
+        final DisplayInfo overrideDisplayInfo = mShouldOverrideDisplayConfiguration
+                ? mDisplayInfo : null;
         mService.mDisplayManagerInternal.setDisplayInfoOverrideFromWindowManager(mDisplayId,
-                mDisplayInfo);
+                overrideDisplayInfo);
 
         mBaseDisplayRect.set(0, 0, dw, dh);
 
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 9f8de58b..5f0769d 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -1117,17 +1117,7 @@
                 throw new IllegalStateException("Display has not been initialialized");
             }
 
-            DisplayContent displayContent = mRoot.getDisplayContent(displayId);
-
-            // Adding a window is an exception where the WindowManagerService can create the
-            // display instead of waiting for the ActivityManagerService to drive creation.
-            if (displayContent == null) {
-                final Display display = mDisplayManager.getDisplay(displayId);
-
-                if (display != null) {
-                    displayContent = mRoot.createDisplayContent(display, null /* controller */);
-                }
-            }
+            final DisplayContent displayContent = getDisplayContentOrCreate(displayId);
 
             if (displayContent == null) {
                 Slog.w(TAG_WM, "Attempted to add window to a display that does not exist: "
@@ -1493,6 +1483,32 @@
         return res;
     }
 
+    /**
+     * Get existing {@link DisplayContent} or create a new one if the display is registered in
+     * DisplayManager.
+     *
+     * NOTE: This should only be used in cases when there is a chance that a {@link DisplayContent}
+     * that corresponds to a display just added to DisplayManager has not yet been created. This
+     * usually means that the call of this method was initiated from outside of Activity or Window
+     * Manager. In most cases the regular getter should be used.
+     * @see RootWindowContainer#getDisplayContent(int)
+     */
+    private DisplayContent getDisplayContentOrCreate(int displayId) {
+        DisplayContent displayContent = mRoot.getDisplayContent(displayId);
+
+        // Create an instance if possible instead of waiting for the ActivityManagerService to drive
+        // the creation.
+        if (displayContent == null) {
+            final Display display = mDisplayManager.getDisplay(displayId);
+
+            if (display != null) {
+                displayContent = mRoot.createDisplayContent(display, null /* controller */);
+            }
+        }
+
+        return displayContent;
+    }
+
     private boolean doesAddToastWindowRequireToken(String packageName, int callingUid,
             WindowState attachedWindow) {
         // Try using the target SDK of the root window
@@ -6987,6 +7003,24 @@
     }
 
     @Override
+    public void dontOverrideDisplayInfo(int displayId) {
+        synchronized (mWindowMap) {
+            final DisplayContent dc = getDisplayContentOrCreate(displayId);
+            if (dc == null) {
+                throw new IllegalArgumentException(
+                        "Trying to register a non existent display.");
+            }
+            // We usually set the override info in DisplayManager so that we get consistent
+            // values when displays are changing. However, we don't do this for displays that
+            // serve as containers for ActivityViews because we don't want letter-/pillar-boxing
+            // during resize.
+            dc.mShouldOverrideDisplayConfiguration = false;
+            mDisplayManagerInternal.setDisplayInfoOverrideFromWindowManager(displayId,
+                    null /* info */);
+        }
+    }
+
+    @Override
     public void registerShortcutKey(long shortcutCode, IShortcutService shortcutKeyReceiver)
             throws RemoteException {
         if (!checkCallingPermission(REGISTER_WINDOW_MANAGER_LISTENERS, "registerShortcutKey")) {