service_manager: More consistent Service lifecycle API

services/service_manager/public/cpp/service_context.h

Index: services/service_manager/public/cpp/service_context.h
diff --git a/services/service_manager/public/cpp/service_context.h b/services/service_manager/public/cpp/service_context.h
index a1af32c503bf700d32bc63d67e3e1d7909de5dc4..f86dfa007868bbe07c987d113aab07b1dce06005 100644
--- a/services/service_manager/public/cpp/service_context.h
+++ b/services/service_manager/public/cpp/service_context.h
@@ -146,6 +146,7 @@ class ServiceContext : public mojom::Service {
   // is unbound and therefore invalid until OnStart() is called.
   mojom::ServiceControlAssociatedPtr service_control_;
 
+  bool service_started_ = false;
   bool service_quit_ = false;
 
   base::Closure connection_lost_closure_;