Change multi-prerender API to include per launcher slots.

chrome/browser/prerender/prerender_manager.h

Index: chrome/browser/prerender/prerender_manager.h
diff --git a/chrome/browser/prerender/prerender_manager.h b/chrome/browser/prerender/prerender_manager.h
index d241358e85a4f0416cc7c5576653533b9c468f0c..0714c9241b4176db877a41b7129cb38323d90c57 100644
--- a/chrome/browser/prerender/prerender_manager.h
+++ b/chrome/browser/prerender/prerender_manager.h
@@ -263,6 +263,12 @@ class PrerenderManager : public base::SupportsWeakPtr<PrerenderManager>,
 
   Profile* profile() const { return profile_; }
 
+  // Classes which will be tested in prerender unit browser tests should use
+  // these methods to get times for comparison, so that the test framework can
+  // mock advancing/retarding time.
+  virtual base::Time GetCurrentTime() const;
+  virtual base::TimeTicks GetCurrentTimeTicks() const;
+
  protected:
   class PrerenderData : public base::SupportsWeakPtr<PrerenderData> {
    public:
@@ -419,8 +425,6 @@ class PrerenderManager : public base::SupportsWeakPtr<PrerenderManager>,
   base::TimeTicks GetExpiryTimeForNavigatedAwayPrerender() const;
 
   void DeleteOldEntries();
-  virtual base::Time GetCurrentTime() const;
-  virtual base::TimeTicks GetCurrentTimeTicks() const;
   virtual PrerenderContents* CreatePrerenderContents(
       const GURL& url,
       const content::Referrer& referrer,