Additional fixes for prerender/instant + browsing history.

chrome/browser/prerender/prerender_contents.cc

Index: chrome/browser/prerender/prerender_contents.cc
diff --git a/chrome/browser/prerender/prerender_contents.cc b/chrome/browser/prerender/prerender_contents.cc
index 23be43dba3771000af4cd146efa123f44ea0fb19..3b05a9c167417109782782039ae63ad9c947ab82 100644
--- a/chrome/browser/prerender/prerender_contents.cc
+++ b/chrome/browser/prerender/prerender_contents.cc
@@ -602,4 +602,13 @@ Value* PrerenderContents::GetAsValue() const {
   return dict_value;
 }
 
+bool PrerenderContents::IsCrossSiteNavigationPending() const {
+  if (!prerender_contents_.get() || !prerender_contents_->tab_contents())
+    return false;
+  const TabContents* tab_contents = prerender_contents_->tab_contents();
+  return (tab_contents->GetSiteInstance() !=
+          tab_contents->GetPendingSiteInstance());
+}
+
+
 }  // namespace prerender