Add <pre> to nesting tags

javatests/org/chromium/distiller/ContentExtractorTest.java

Index: javatests/org/chromium/distiller/ContentExtractorTest.java
diff --git a/javatests/org/chromium/distiller/ContentExtractorTest.java b/javatests/org/chromium/distiller/ContentExtractorTest.java
index 0b03d6a9dd95b2177f5233aaa61e93beb6229ef7..36ecc5042dabf1e9ac3f773e2c81f4db27c9089c 100644
--- a/javatests/org/chromium/distiller/ContentExtractorTest.java
+++ b/javatests/org/chromium/distiller/ContentExtractorTest.java
@@ -485,6 +485,17 @@ public class ContentExtractorTest extends DomDistillerJsTestCase {
                 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);