entd: require a per-entd-invocation session id in every request

main.cc

Index: main.cc
diff --git a/main.cc b/main.cc
index 14c70a91abd62af90884faac1be9833cefca73ef..299ece75efdb5f015dd77bd7d00d938edbc8f12e 100644
--- a/main.cc
+++ b/main.cc
@@ -56,6 +56,8 @@ static const char *kLibcrosLocation = "libcros-location";
 
 static const char *kCallbackOrigin = "callback-origin";
 
+static const char *kSessionId = "session-id";
+
 }  // namespace switches
 
 // Return values:
@@ -164,6 +166,13 @@ int main(int argc, char** argv) {
         entd::CallbackServer::required_origin;
   }
 
+  if (cl->HasSwitch(switches::kSessionId)) {
+    entd::CallbackServer::set_session_id(cl->GetSwitchValueASCII(
+        switches::kSessionId));
+    LOG(INFO) << "Setting session id: " <<
+        entd::CallbackServer::session_id();
+  }
+
   entd::Entd d;
   d.Initialize();