V4Only: In V4Only mode use PVer4 for all SafeBrowsing operations

chrome/browser/safe_browsing/safe_browsing_service.h

Index: chrome/browser/safe_browsing/safe_browsing_service.h
diff --git a/chrome/browser/safe_browsing/safe_browsing_service.h b/chrome/browser/safe_browsing/safe_browsing_service.h
index d8de6da53ab3f122bc80e856d4a987f64990a519..27e15b03e9de51ac031f5fda6557acc9ee0be8dc 100644
--- a/chrome/browser/safe_browsing/safe_browsing_service.h
+++ b/chrome/browser/safe_browsing/safe_browsing_service.h
@@ -125,13 +125,16 @@ class SafeBrowsingService : public base::RefCountedThreadSafe<
 
   const scoped_refptr<SafeBrowsingUIManager>& ui_manager() const;
 
+  // This returns either the v3 or the v4 database manager, depending on
+  // the experiment settings.
   const scoped_refptr<SafeBrowsingDatabaseManager>& database_manager() const;
 
   SafeBrowsingProtocolManager* protocol_manager() const;
 
   SafeBrowsingPingManager* ping_manager() const;
 
-  const scoped_refptr<V4LocalDatabaseManager>& v4_local_database_manager()
+  // This may be NULL if v4 is not enabled by experiment.
+  const scoped_refptr<SafeBrowsingDatabaseManager>& v4_local_database_manager()
       const;
 
   // Returns a preference validation delegate that adds incidents to the
@@ -263,6 +266,10 @@ class SafeBrowsingService : public base::RefCountedThreadSafe<
   // Accessed on UI thread.
   bool enabled_by_prefs_;
 
+  // Whether SafeBrowsing needs to be enabled in V4Only mode. In this mode, all
+  // SafeBrowsing decisions are made using the PVer4 implementation.
+  bool enabled_v4_only_;
+
   // Tracks existing PrefServices, and the safe browsing preference on each.
   // This is used to determine if any profile is currently using the safe
   // browsing service, and to start it up or shut it down accordingly.