weak_ptr_factory.cpp:43:38: warning: [chromium-style] WeakPtrFactory members which refer to their outer class must be the last member in the outer class definition.
  base::WeakPtrFactory<FactoryFirst> factory_;
                                     ^
weak_ptr_factory.cpp:49:39: warning: [chromium-style] WeakPtrFactory members which refer to their outer class must be the last member in the outer class definition.
  base::WeakPtrFactory<FactoryMiddle> factory_;
                                      ^
weak_ptr_factory.cpp:55:44: warning: [chromium-style] WeakPtrFactory members which refer to their outer class must be the last member in the outer class definition.
  base::WeakPtrFactory<TwoFactoriesOneBad> factory1_;
                                           ^
3 warnings generated.