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 e7fba706be4a998e104da0197e47026ac946ed4c..5c4866f905caab7f5f96bda32c2b5e0361c756c0 100644
--- a/chrome/browser/prerender/prerender_browsertest.cc
+++ b/chrome/browser/prerender/prerender_browsertest.cc
@@ -307,11 +307,12 @@ class TestPrerenderContents : public PrerenderContents {
 
   virtual void AddPendingPrerender(
       base::WeakPtr<PrerenderHandle> weak_prerender_handle,
+      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();