Remove "<HR>" tags to import Firefox bookmarks correctly.

chrome/test/data/bookmark_html_reader/firefox23.html

Index: chrome/test/data/bookmark_html_reader/firefox23.html
diff --git a/chrome/test/data/bookmark_html_reader/firefox23.html b/chrome/test/data/bookmark_html_reader/firefox23.html
new file mode 100644
index 0000000000000000000000000000000000000000..93943b8db1b69a0cfd1dcfc1b7fb8e649b2158fb
--- /dev/null
+++ b/chrome/test/data/bookmark_html_reader/firefox23.html
@@ -0,0 +1,16 @@
+<!DOCTYPE NETSCAPE-Bookmark-file-1>
+<!-- This is an automatically generated file.
+     It will be read and overwritten.
+     DO NOT EDIT! -->
+<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8">
+<TITLE>Bookmarks</TITLE>
+<H1>Bookmarks Menu</H1>
+
+<DL><p>
+    <DT><A HREF="https://www.google.com/" ADD_DATE="1376102167" LAST_MODIFIED="1376102193">Google</A>
+    <HR>    <HR>    <DT><H3 ADD_DATE="1376102198" LAST_MODIFIED="1376102992">Chromium</H3>
+    <DL><p>
+        <DT><A HREF="https://code.google.com/p/chromium/issues/list" ADD_DATE="1376102304" LAST_MODIFIED="1376102318">Issues</A>
+        <HR>        <DT><A HREF="http://code.google.com/p/chromium/codesearch" ADD_DATE="1376102224" LAST_MODIFIED="1376102251">CodeSearch</A>
+    </DL><p>
+    <HR></DL><p>