Transfer user agent override info between browser and renderer

content/public/browser/navigation_controller.h

Index: content/public/browser/navigation_controller.h
diff --git a/content/public/browser/navigation_controller.h b/content/public/browser/navigation_controller.h
index c9c1a01384a76cd56736af5fe1bc2e9e5c4ec4fd..7cf6fdf5c2dcc8abcd7537f514443768c8ef90a9 100644
--- a/content/public/browser/navigation_controller.h
+++ b/content/public/browser/navigation_controller.h
@@ -167,6 +167,15 @@ class NavigationController {
                                    PageTransition type,
                                    const std::string& extra_headers) = 0;
 
+  // Same as LoadURL, but allows overriding the user agent of the
+  // NavigationEntry before it loads.
+  virtual void LoadURLWithUserAgentOverride(const GURL& url,
+                                            const Referrer& referrer,
+                                            PageTransition type,
+                                            bool is_renderer_initiated,
+                                            const std::string& extra_headers,
+                                            bool is_overriding_user_agent) = 0;
+
   // Behaves like LoadURL() and LoadURLFromRenderer() but marks the new
   // navigation as being transferred from one RVH to another. In this case the
   // browser can recycle the old request once the new renderer wants to