Template methods on Timer classes instead of the classes themselves.

components/copresence/timed_map.h

Index: components/copresence/timed_map.h
diff --git a/components/copresence/timed_map.h b/components/copresence/timed_map.h
index bcd7149ba08b51d82d48b77d8bc54221fe60ffde..f6c58591f898d7c445ef9eb63737a3bd81d51732 100644
--- a/components/copresence/timed_map.h
+++ b/components/copresence/timed_map.h
@@ -96,7 +96,7 @@ class TimedMap {
   const ValueType kEmptyValue;
 
   scoped_ptr<base::TickClock> clock_;
-  base::RepeatingTimer<TimedMap> timer_;
+  base::RepeatingTimer timer_;
   const base::TimeDelta lifetime_;
   const size_t max_elements_;
   std::map<KeyType, ValueType> map_;