title: Android M permission grant callback
body: <p>I am testing the permission system on the Android M Dev Preview. I have a question about the callback function. The Activity class has a new API:</p>
  
  <pre><code>public void onRequestPermissionsResult (int requestCode, 
                 String[] permissions, int[] grantResults) { }
  </code></pre>
  
  <p>I want to ask why are permissions and grantResults arguments defined as arrays ? I know that multiple permissions can be asked at the same time using <code>requestPermissions()</code>, but if a request code is used for a permission set of request, wouldn't it suffice to just have an integer grantResults (not sure about permissions argument) ?</p>