shill_manager: add APIs for setting interface modes

This is needed to allow apmanager to setup an AP/station mode
interface when starting/stopping an AP service.

Bug: 25113165
TEST=Device setup on Brillo boards

Change-Id: I2b5b708409fe1c59e0333b1e4347d46ba0162847
diff --git a/shill_manager.cc b/shill_manager.cc
index 1e5c2fa..2261b8e 100644
--- a/shill_manager.cc
+++ b/shill_manager.cc
@@ -51,6 +51,18 @@
   claimed_interfaces_.erase(interface_name);
 }
 
+#if defined(__BRILLO__)
+bool ShillManager::SetupApModeInterface(string* interface_name) {
+  CHECK(shill_proxy_) << "Proxy not initialized yet";
+  return shill_proxy_->SetupApModeInterface(interface_name);
+}
+
+bool ShillManager::SetupStationModeInterface(string* interface_name) {
+  CHECK(shill_proxy_) << "Proxy not initialized yet";
+  return shill_proxy_->SetupStationModeInterface(interface_name);
+}
+#endif  // __BRILLO__
+
 void ShillManager::OnShillServiceAppeared() {
   LOG(INFO) << __func__;
   // Claim all interfaces from shill service in case this is a new instance.