Add info about user agent overrides to WebContents

chrome/browser/sessions/session_service_test_helper.h

Index: chrome/browser/sessions/session_service_test_helper.h
diff --git a/chrome/browser/sessions/session_service_test_helper.h b/chrome/browser/sessions/session_service_test_helper.h
index 382f018724559785808216a067b10bb96b37897b..f5e3474eee7d33c1095061d45030b93fd7437055 100644
--- a/chrome/browser/sessions/session_service_test_helper.h
+++ b/chrome/browser/sessions/session_service_test_helper.h
@@ -40,6 +40,10 @@ class SessionServiceTestHelper {
                             const SessionID& tab_id,
                             const std::string& extension_app_id);
 
+  void SetTabUserAgentOverride(const SessionID& window_id,
+                               const SessionID& tab_id,
+                               const std::string& user_agent_override);
+
   // Reads the contents of the last session.
   void ReadWindows(std::vector<SessionWindow*>* windows);