title: PDFRenderer unable to display a file
body: <p>I'm using API Level 21 and I'm trying to display a PDF downloaded from internet and stored in the cache directory.</p>
  
  <pre><code>   private void openRenderer(Context context) throws IOException {
      Log.d("NoiPA", "Opening PDF File: " + pdfPath);
      // In this sample, we read a PDF from the assets directory.
      mFileDescriptor = ParcelFileDescriptor.open(new File(pdfPath),ParcelFileDescriptor.MODE_READ_ONLY);
      //mFileDescriptor = context.getAssets().openFd(pdfPath).getParcelFileDescriptor();
      // This is the PdfRenderer we use to render the PDF.
      mPdfRenderer = new PdfRenderer(mFileDescriptor);
  }
  </code></pre>
  
  <p>The code above makes the app crash with the following stack trace:</p>
  
  <pre><code>Download: Completed -&gt; Showing PDF
  onAttach -&gt; pdfPath: /data/data/com.vitobellini.noipa/cache/MAG 2016.pdf
  Opening PDF File: /data/data/com.vitobellini.noipa/cache/MAG 2016.pdf
  java.io.IOException: not create document. Error:
       at android.graphics.pdf.PdfRenderer.nativeCreate(Native Method)
       at android.graphics.pdf.PdfRenderer.&lt;init&gt;(PdfRenderer.java:149)
       at com.vitobellini.noipa.PdfRendererFragment.openRenderer(PdfRendererFragment.java:151)
       at com.vitobellini.noipa.PdfRendererFragment.onAttach(PdfRendererFragment.java:115)
       at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1019)
       at android.support.v4.app.BackStackRecord.setLastIn(BackStackRecord.java:779)
       at android.support.v4.app.BackStackRecord.calculateFragments(BackStackRecord.java:819)
       at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:660)
       at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1617)
       at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:517)
       at android.os.Handler.handleCallback(Handler.java:739)
       at android.os.Handler.dispatchMessage(Handler.java:95)
       at android.os.Looper.loop(Looper.java:135)
       at android.app.ActivityThread.main(ActivityThread.java:5221)
       at java.lang.reflect.Method.invoke(Native Method)
       at java.lang.reflect.Method.invoke(Method.java:372)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
  </code></pre>
  
  <p>I cannot explain to myself why that code is not working, anyone knows how to fix it?</p>