Fix safe mode and KeyEvent.getMaxKeyCode().

Bug: 2901731
Change-Id: I78617c1b9dee3790fc590e5af4b5083368873184
diff --git a/include/ui/InputReader.h b/include/ui/InputReader.h
index f162231..71c6c51 100644
--- a/include/ui/InputReader.h
+++ b/include/ui/InputReader.h
@@ -454,6 +454,8 @@
     virtual void reset();
     virtual void process(const RawEvent* rawEvent);
 
+    virtual int32_t getScanCodeState(uint32_t sourceMask, int32_t scanCode);
+
 private:
     // Amount that trackball needs to move in order to generate a key event.
     static const int32_t TRACKBALL_MOVEMENT_THRESHOLD = 6;