Display magnifier does not release its surface on destroy.

Change-Id: I0b9448c8859b0167632652060b08072dc8c9c0a5

services/java/com/android/server/wm/DisplayMagnifier.java

@@ -228,6 +228,10 @@ final class DisplayMagnifier {
         return spec;
     }
 
+    public void destroyLocked() {
+        mMagnifedViewport.destroyWindow();
+    }
+
     /** NOTE: This has to be called within a surface transaction. */
     public void drawMagnifiedRegionBorderIfNeededLocked() {
         mMagnifedViewport.drawWindowIfNeededLocked();
@@ -258,7 +262,7 @@ final class DisplayMagnifier {
         private final int mBorderWidth;
         private final int mHalfBorderWidth;
 
-        private ViewportWindow mWindow;
+        private final ViewportWindow mWindow;
 
         private boolean mFullRedrawNeeded;
 
@@ -459,6 +463,10 @@ final class DisplayMagnifier {
             mWindow.drawIfNeeded();
         }
 
+        public void destroyWindow() {
+            mWindow.releaseSurface();
+        }
+
         private final class ViewportWindow {
             private static final String SURFACE_TITLE = "Magnification Overlay";
 
@@ -640,6 +648,10 @@ final class DisplayMagnifier {
                     }
                 }
             }
+
+            public void releaseSurface() {
+                mSurface.release();
+            }
         }
     }
 

services/java/com/android/server/wm/WindowManagerService.java

@@ -3039,7 +3039,10 @@ public class WindowManagerService extends IWindowManager.Stub
                 mDisplayMagnifier = new DisplayMagnifier(this, callbacks);
             } else {
                 if (callbacks == null) {
-                    mDisplayMagnifier = null;
+                    if (mDisplayMagnifier != null) {
+                        mDisplayMagnifier.destroyLocked();
+                        mDisplayMagnifier = null;
+                    }
                 } else {
                     throw new IllegalStateException("Magnification callbacks already set!");
                 }