Remove activity_log's Util::DropObsoleteTables().

chrome/browser/extensions/activity_log/activity_log_policy.h

Index: chrome/browser/extensions/activity_log/activity_log_policy.h
diff --git a/chrome/browser/extensions/activity_log/activity_log_policy.h b/chrome/browser/extensions/activity_log/activity_log_policy.h
index 997e34a2696b5d1ebdae3dc19a8ebf6c7b7bb56d..004f9fccd256b19d6b358ec195fbd77f08e8f8ff 100644
--- a/chrome/browser/extensions/activity_log/activity_log_policy.h
+++ b/chrome/browser/extensions/activity_log/activity_log_policy.h
@@ -120,12 +120,6 @@ class ActivityLogPolicy {
                                           int64_t* early_bound,
                                           int64_t* late_bound);
 
-    // Deletes obsolete database tables from an activity log database.  This
-    // can be used in InitDatabase() methods of ActivityLogDatabasePolicy
-    // subclasses to clean up data from old versions of the activity logging
-    // code.  Returns true on success, false on database error.
-    static bool DropObsoleteTables(sql::Connection* db);
-
    private:
     DISALLOW_IMPLICIT_CONSTRUCTORS(Util);
   };