Android: creates fifo for test runners in internal directory.

testing/android/java/src/org/chromium/native_test/ChromeNativeTestActivity.java

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.native_test;
 
 import android.app.Activity;
 import android.content.Context;
 import android.os.Bundle;
 import android.os.Environment;
@@ skipping 52 matching lines @@
             }
         } catch (UnsatisfiedLinkError e) {
             Log.e(TAG, "Unable to load lib" + mLibrary + ".so: " + e);
             nativeTestFailed();
             throw e;
         }
     }
 
     private void runTests() {
         // This directory is used by build/android/pylib/test_package_apk.py.
-        File filesDir = new File(Environment.getExternalStorageDirectory(),
-                                 "native_tests/");
-        filesDir.mkdirs();
-        nativeRunTests(filesDir.getAbsolutePath(), getApplicationContext());
+        nativeRunTests(getFilesDir().getAbsolutePath(), getApplicationContext());
     }
 
     // Signal a failure of the native test loader to python scripts
     // which run tests.  For example, we look for
     // RUNNER_FAILED build/android/test_package.py.
     private void nativeTestFailed() {
         Log.e(TAG, "[ RUNNER_FAILED ] could not load native library");
     }
 
     private void loadLibrary() throws UnsatisfiedLinkError {
         Log.i(TAG, "loading: " + mLibrary);
         System.loadLibrary(mLibrary);
         Log.i(TAG, "loaded: " + mLibrary);
     }
 
     private native void nativeRunTests(String filesDir, Context appContext);
 }