Fix prerender histograms for multiple prerender case.

chrome/browser/prerender/prerender_browsertest.cc

Index: chrome/browser/prerender/prerender_browsertest.cc
diff --git a/chrome/browser/prerender/prerender_browsertest.cc b/chrome/browser/prerender/prerender_browsertest.cc
index 33dd892fa33d651301f878ffbc7dc4ef6f84316c..279d71e73156c7599d887c33fb3ef077d09f0548 100644
--- a/chrome/browser/prerender/prerender_browsertest.cc
+++ b/chrome/browser/prerender/prerender_browsertest.cc
@@ -306,11 +306,12 @@ class TestPrerenderContents : public PrerenderContents {
 
   virtual void AddPendingPrerender(
       base::WeakPtr<PrerenderHandle> weak_prerender_handle,
+      const Origin origin,
       const GURL& url,
       const content::Referrer& referrer,
       const gfx::Size& size) OVERRIDE {
     PrerenderContents::AddPendingPrerender(
-        weak_prerender_handle, url, referrer, size);
+        weak_prerender_handle, origin, url, referrer, size);
     if (expected_pending_prerenders_ > 0 &&
         pending_prerenders().size() == expected_pending_prerenders_) {
       MessageLoop::current()->Quit();