Add <pre> to nesting tags

javatests/org/chromium/distiller/ContentExtractorTest.java

 // Copyright 2014 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.distiller;
 
 import com.google.gwt.dom.client.Document;
 import com.google.gwt.dom.client.Element;
 
 public class ContentExtractorTest extends DomDistillerJsTestCase {
@@ skipping 467 matching lines @@
         ContentExtractor extractor = new ContentExtractor(mRoot);
         String extractedContent = extractor.extractContent();
         assertEquals("<BLOCKQUOTE>" +
                         "<p>" + CONTENT_TEXT + "</p>" +
                         "<p>" + CONTENT_TEXT + "</p>" +
                         "<p>" + CONTENT_TEXT + "</p>" +
                      "</BLOCKQUOTE>",
                 TestUtil.removeAllDirAttributes(extractedContent));
     }
 
+    public void testDiscardBlockquoteWithoutContent() {
+        assertExtractor("", "<BLOCKQUOTE></BLOCKQUOTE>");
+    }
+
+    public void testPreservePre() {
+        final String article = CONTENT_TEXT + CONTENT_TEXT + CONTENT_TEXT;
+        final String html = "<h1>" + CONTENT_TEXT + "</h1><PRE><kbd>" + article + "</kbd></PRE>";
+
+        assertExtractor(html, html);
+    }
+
     private void assertExtractor(String expected, String html) {
         mBody.setInnerHTML("");
         Element div = TestUtil.createDiv(0);
         mBody.appendChild(div);
 
         div.setInnerHTML(html);
         ContentExtractor extractor = new ContentExtractor(mRoot);
         String extractedContent = extractor.extractContent();
         assertEquals(expected, TestUtil.removeAllDirAttributes(extractedContent));
     }
@@ skipping 76 matching lines @@
 
         final String htmlArticle =
             "<h1>" + CONTENT_TEXT + "</h1>" +
             "<div itemscope itemtype=\"http://schema.org/Movie\">" + article + "</div>";
         final String expected = "<h1>" + CONTENT_TEXT + "</h1>" + article;
 
         // Non-article schema.org types should not use the fast path.
         assertExtractor(expected, htmlArticle);
     }
 }