[Cronet] Purge storage directory if version does not match

components/cronet/android/test/javatests/src/org/chromium/net/QuicTest.java

 // Copyright 2015 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.net;
 
 import android.test.suitebuilder.annotation.LargeTest;
 import android.test.suitebuilder.annotation.SmallTest;
 
 import org.chromium.base.Log;
@@ skipping 144 matching lines @@
         assertEquals(expectedContent, callback2.mResponseAsString);
         assertEquals("quic/1+spdy/3", callback2.mResponseInfo.getNegotiatedProtocol());
         // The total received bytes should be larger than the content length, to account for
         // headers.
         assertTrue(callback2.mResponseInfo.getReceivedBytesCount() > expectedContent.length());
     }
 
     // Returns whether a file contains a particular string.
     @SuppressFBWarnings("OBL_UNSATISFIED_OBLIGATION_EXCEPTION_EDGE")
     private boolean fileContainsString(String filename, String content) throws IOException {
-        File file = new File(CronetTestFramework.getTestStorage(getContext()) + "/" + filename);
+        File file =
+                new File(CronetTestFramework.getTestStorage(getContext()) + "/prefs/" + filename);
         FileInputStream fileInputStream = new FileInputStream(file);
         byte[] data = new byte[(int) file.length()];
         fileInputStream.read(data);
         fileInputStream.close();
         return new String(data, "UTF-8").contains(content);
     }
 }