Transfer user agent override info between browser and renderer

chrome/browser/prerender/prerender_config.h

Index: chrome/browser/prerender/prerender_config.h
diff --git a/chrome/browser/prerender/prerender_config.h b/chrome/browser/prerender/prerender_config.h
index 46b83a55300d6ccdf571a0de2ed33dc353e80cbe..97abcbd0ccafaf7ead67678dbddfc1e48ca15152 100644
--- a/chrome/browser/prerender/prerender_config.h
+++ b/chrome/browser/prerender/prerender_config.h
@@ -32,6 +32,12 @@ struct Config {
   // The default tab bounds used as the prerenderer tab size when the active tab
   // cannot be accessed.
   gfx::Rect default_tab_bounds;
+
+  // User agent being used as an override for the WebContents.
+  std::string user_agent_override;
+
+  // Is the user agent being overridden for this NavigationEntry?
+  bool is_overriding_user_agent;
 };
 
 }  // namespace prerender