Reland: chromeos: Convert ash VPNDelegate interface to mojo

ash/common/wm_shell.h

Index: ash/common/wm_shell.h
diff --git a/ash/common/wm_shell.h b/ash/common/wm_shell.h
index 2c7a1548972c36a3c193ec513650f6f6a71cd521..b7adf68b69edb12a1230eb3f5a131ec648ae1cdd 100644
--- a/ash/common/wm_shell.h
+++ b/ash/common/wm_shell.h
@@ -93,6 +93,7 @@ class WindowState;
 
 #if defined(OS_CHROMEOS)
 class LogoutConfirmationController;
+class VpnList;
 #endif
 
 // Similar to ash::Shell. Eventually the two will be merged.
@@ -425,6 +426,8 @@ class ASH_EXPORT WmShell {
     return logout_confirmation_controller_.get();
   }
 
+  VpnList* vpn_list() { return vpn_list_.get(); }
+
   // TODO(jamescook): Remove this when VirtualKeyboardController has been moved.
   virtual void ToggleIgnoreExternalKeyboard() = 0;
 
@@ -513,6 +516,7 @@ class ASH_EXPORT WmShell {
 
 #if defined(OS_CHROMEOS)
   std::unique_ptr<LogoutConfirmationController> logout_confirmation_controller_;
+  std::unique_ptr<VpnList> vpn_list_;
 #endif
 };