Fix window leak problems in settings.

There were window leak in the settings application.
These leak happens when an AlertDialog displays, rotate the phone,
then it would cause window leak.

Change-Id: I914897bf657933efea72eeea66076dc288098420

src/com/android/settings/bluetooth/CachedBluetoothDevice.java

@@ -71,6 +71,8 @@ public class CachedBluetoothDevice implements Comparable<CachedBluetoothDevice>
 
     private final LocalBluetoothManager mLocalManager;
 
+    private AlertDialog mDialog = null;
+
     private List<Callback> mCallbacks = new ArrayList<Callback>();
 
     /**
@@ -375,12 +377,29 @@ public class CachedBluetoothDevice implements Comparable<CachedBluetoothDevice>
             }
         };
 
-        new AlertDialog.Builder(context)
-                .setTitle(getName())
-                .setMessage(message)
-                .setPositiveButton(android.R.string.ok, disconnectListener)
-                .setNegativeButton(android.R.string.cancel, null)
-                .show();
+        if (mDialog == null) {
+            mDialog = new AlertDialog.Builder(context)
+                    .setPositiveButton(android.R.string.ok, disconnectListener)
+                    .setNegativeButton(android.R.string.cancel, null)
+                    .create();
+        } else {
+            if (mDialog.isShowing()) {
+                mDialog.dismiss();
+            }
+        }
+        mDialog.setTitle(getName());
+        mDialog.setMessage(message);
+        mDialog.show();
+    }
+
+    @Override
+    protected void finalize() throws Throwable {
+        if (mDialog != null) {
+            mDialog.dismiss();
+            mDialog = null;
+        }
+
+        super.finalize();
     }
 
     public void connect() {