Add observer interface to PrerenderContents.

chrome/browser/prerender/prerender_manager.cc

Index: chrome/browser/prerender/prerender_manager.cc
diff --git a/chrome/browser/prerender/prerender_manager.cc b/chrome/browser/prerender/prerender_manager.cc
index 1cab97eed6ea7bf58e906bf79d7cfe39892a9370..192f2c60af67c908476ead25f5bc850c81d0a215 100644
--- a/chrome/browser/prerender/prerender_manager.cc
+++ b/chrome/browser/prerender/prerender_manager.cc
@@ -419,7 +419,7 @@ bool PrerenderManager::MaybeUsePrerenderedPage(WebContents* web_contents,
   histograms_->RecordPerSessionCount(prerender_contents->origin(),
                                      ++prerenders_per_session_count_);
   histograms_->RecordUsedPrerender(prerender_contents->origin());
-  prerender_contents->set_final_status(FINAL_STATUS_USED);
+  prerender_contents->SetFinalStatus(FINAL_STATUS_USED);
 
   RenderViewHost* new_render_view_host =
       prerender_contents->prerender_contents()->web_contents()->
@@ -1183,7 +1183,7 @@ PrerenderContents* PrerenderManager::CreatePrerenderContents(
     uint8 experiment_id) {
   DCHECK(CalledOnValidThread());
   return prerender_contents_factory_->CreatePrerenderContents(
-      this, prerender_tracker_, profile_, url, referrer, origin, experiment_id);
+      this, profile_, url, referrer, origin, experiment_id);
 }
 
 void PrerenderManager::SortActivePrerenders() {