Fixed IBinder cast to IWindow for mFocusedWindow (1/3)

Use the correct cast from IBinder to IWindow

Bug: 121122996
Test: mFocusedWindow no longer remains null

Change-Id: Ia208e129a8cce960620c5edd42f55af0d89914fc
diff --git a/services/core/java/com/android/server/input/InputManagerService.java b/services/core/java/com/android/server/input/InputManagerService.java
index 8810d1d..45a9bc0 100644
--- a/services/core/java/com/android/server/input/InputManagerService.java
+++ b/services/core/java/com/android/server/input/InputManagerService.java
@@ -1761,14 +1761,13 @@
 
     // Native callback
     private void notifyFocusChanged(IBinder token) {
-        if (mFocusedWindow != token) {
-            if (mFocusedWindowHasCapture) {
-                setPointerCapture(false);
-            }
-            if (token instanceof IWindow) {
-                mFocusedWindow = (IWindow) token;
-            }
+        if (mFocusedWindow.asBinder() == token) {
+            Log.w(TAG, "notifyFocusChanged called with unchanged mFocusedWindow=" + mFocusedWindow);
+            return;
         }
+
+        setPointerCapture(false);
+        mFocusedWindow = IWindow.Stub.asInterface(token);
     }
 
     // Native callback.