Use content::Referrer to pass around referrers in the plugin code

content/child/npapi/webplugin_delegate.h

Index: content/child/npapi/webplugin_delegate.h
diff --git a/content/child/npapi/webplugin_delegate.h b/content/child/npapi/webplugin_delegate.h
index eaef885a38cd2824743795a384dd12ec9b399215..8f13c8d80d2ad33ce021ad1a4e9b724e6dd489e4 100644
--- a/content/child/npapi/webplugin_delegate.h
+++ b/content/child/npapi/webplugin_delegate.h
@@ -28,6 +28,7 @@ class Rect;
 
 namespace content {
 
+struct Referrer;
 class WebPluginResourceClient;
 
 // This is the interface that a plugin implementation needs to provide.
@@ -138,7 +139,7 @@ class WebPluginDelegate {
                         const std::string& method,
                         const char* buf,
                         unsigned int len,
-                        const GURL& referrer,
+                        const Referrer& referrer,
                         bool notify_redirects,
                         bool is_plugin_src_load,
                         int origin_pid,