permissionrequest API for guest Download.

chrome/browser/download/download_request_limiter.h

Index: chrome/browser/download/download_request_limiter.h
diff --git a/chrome/browser/download/download_request_limiter.h b/chrome/browser/download/download_request_limiter.h
index 16ebfaf36cbc2ec35e12585663d5b8f77e808c17..dae0506e9e06f27462d23ce2e52465ce2a79a1b1 100644
--- a/chrome/browser/download/download_request_limiter.h
+++ b/chrome/browser/download/download_request_limiter.h
@@ -218,6 +218,13 @@ class DownloadRequestLimiter
                        const std::string& request_method,
                        const Callback& callback);
 
+  // Invoked when decision to download has been made.
+  void OnCanDownloadDecided(content::WebContents* originating_web_contents,
+                            int request_id,
+                            const std::string& request_method,
+                            const Callback& orig_callback,
+                            bool allow);
+
   // Invoked on the UI thread. Schedules a call to NotifyCallback on the io
   // thread.
   void ScheduleNotification(const Callback& callback, bool allow);
@@ -234,6 +241,10 @@ class DownloadRequestLimiter
   typedef std::map<content::WebContents*, TabDownloadState*> StateMap;
   StateMap state_map_;
 
+  // Weak ptr factory used when |CanDownload| asks the delegate asynchronously
+  // about the download.
+  base::WeakPtrFactory<DownloadRequestLimiter> factory_;
+
   DISALLOW_COPY_AND_ASSIGN(DownloadRequestLimiter);
 };