Remove unused Keyboard.purgeKeyboardAndClosing method

Change-Id: Ia09ac04b0edca2a22d64ba83e054b115fe8851a6
diff --git a/java/src/com/android/inputmethod/keyboard/KeyboardView.java b/java/src/com/android/inputmethod/keyboard/KeyboardView.java
index b7584d4..7fc68e0 100644
--- a/java/src/com/android/inputmethod/keyboard/KeyboardView.java
+++ b/java/src/com/android/inputmethod/keyboard/KeyboardView.java
@@ -1029,6 +1029,7 @@
         cancelAllMessages();
         onCancelMoreKeysPanel();
         mInvalidateAllKeys = true;
+        mKeyboard = null;
         requestLayout();
     }
 
@@ -1062,11 +1063,6 @@
         return false;
     }
 
-    public void purgeKeyboardAndClosing() {
-        mKeyboard = null;
-        closing();
-    }
-
     @Override
     protected void onDetachedFromWindow() {
         super.onDetachedFromWindow();