title: Disable filesystem browsing in Fennec
body: <p>I'm developing custom AOSP 4.4 firmware for custom Android device.
  I'm using Fennec (Firefox for Android) as default browser.
  My custom AOSP does not pass Android Compatibility Testsuit.</p>
  
  <p>Link to test: <a href="http://androidxref.com/4.4.2_r2/xref/cts/tests/tests/security/src/android/security/cts/BrowserTest.java" rel="nofollow">http://androidxref.com/4.4.2_r2/xref/cts/tests/tests/security/src/android/security/cts/BrowserTest.java</a></p>
  
  <p>testBrowserPrivateDataAccess()  test fails.
  This test checks if browser is able to explore root filesystem and download files from it. To access root filesystem I enter file:/// in Fennec browser. I am able to download system applications, from /system/app folder, etc. Such behavior is not desirable.</p>
  
  <p>I have checked this issue on fresh Firefox and Firefox Beta from PlayStore. I was able to reproduce it only on tablets (LG G Pad 8.3, Nexus 10), not reproducible on (Nexus 4, HTC Sensation, Nexus 5).</p>
  
  <p>I can build Fennec by myself, from sources. Can anyone help me how I can disable file exploring through Fennec?</p>
  
  <p>Tnx.</p>