Add Clone and disallow copy construction for NavigationEntryImpl.

content/browser/site_instance_impl_unittest.cc

Index: content/browser/site_instance_impl_unittest.cc
diff --git a/content/browser/site_instance_impl_unittest.cc b/content/browser/site_instance_impl_unittest.cc
index bfa1664694da605d3ed89e5c0f699c48fe0ab2a4..dd7c36096d5289813f7467d32a0cc8541b7eb097 100644
--- a/content/browser/site_instance_impl_unittest.cc
+++ b/content/browser/site_instance_impl_unittest.cc
@@ -265,7 +265,7 @@ TEST_F(SiteInstanceTest, CloneNavigationEntry) {
       instance1, 0, url, Referrer(), base::string16(), ui::PAGE_TRANSITION_LINK,
       false);
   // Clone the entry
-  NavigationEntryImpl* e2 = new NavigationEntryImpl(*e1);
+  NavigationEntryImpl* e2 = e1->Clone();
 
   // Should be able to change the SiteInstance of the cloned entry.
   e2->set_site_instance(instance2);