Revert of chromeos: Convert ash VPNDelegate interface to mojo

ash/mus/system_tray_delegate_mus.cc

Index: ash/mus/system_tray_delegate_mus.cc
diff --git a/ash/mus/system_tray_delegate_mus.cc b/ash/mus/system_tray_delegate_mus.cc
index 8d18bc5e090bc70281c280ab60de7ae50a38e97f..b1ab43f0d674012e79fd005ed1dc5411f0de4fbf 100644
--- a/ash/mus/system_tray_delegate_mus.cc
+++ b/ash/mus/system_tray_delegate_mus.cc
@@ -5,6 +5,7 @@
 #include "ash/mus/system_tray_delegate_mus.h"
 
 #include "ash/common/system/networking_config_delegate.h"
+#include "ash/mus/vpn_delegate_mus.h"
 
 namespace ash {
 namespace {
@@ -29,7 +30,8 @@
 }  // namespace
 
 SystemTrayDelegateMus::SystemTrayDelegateMus()
-    : networking_config_delegate_(new StubNetworkingConfigDelegate) {}
+    : networking_config_delegate_(new StubNetworkingConfigDelegate),
+      vpn_delegate_(new VPNDelegateMus) {}
 
 SystemTrayDelegateMus::~SystemTrayDelegateMus() {
 }
@@ -39,4 +41,8 @@
   return networking_config_delegate_.get();
 }
 
+VPNDelegate* SystemTrayDelegateMus::GetVPNDelegate() const {
+  return vpn_delegate_.get();
+}
+
 }  // namespace ash