[Easy Unlock] Port the BluetoothThrottler class to native code.

components/proximity_auth/connection_observer.h

Index: components/proximity_auth/connection_observer.h
diff --git a/components/proximity_auth/connection_observer.h b/components/proximity_auth/connection_observer.h
index 89bf9741c7056e62f0a0ff9f9ab42d70b8a85b11..27cfb35a979f39d559de5a82bbe89bf0eb769173 100644
--- a/components/proximity_auth/connection_observer.h
+++ b/components/proximity_auth/connection_observer.h
@@ -15,8 +15,8 @@ class WireMessage;
 class ConnectionObserver {
  public:
   // Called when the |connection|'s status changes from |old_status| to
-  // |new_status|.
-  virtual void OnConnectionStatusChanged(const Connection& connection,
+  // |new_status|. The |connectoin| is guaranteed to be non-null.
+  virtual void OnConnectionStatusChanged(Connection* connection,
                                          Connection::Status old_status,
                                          Connection::Status new_status) {}