scene_graph → common Relation

File in drake/examples/scene_graph	Includes file in drake/common
bouncing_ball_plant.h	drake_copyable.h
bouncing_ball_vector.h	drake_bool.h
bouncing_ball_vector.h	dummy_value.h
bouncing_ball_vector.h	symbolic / expression.h
bouncing_ball_vector.h	name_value.h
bouncing_ball_vector.h	never_destroyed.h
solar_system.h	drake_copyable.h