Rate limit programmatic update checks for extensions

extensions/browser/updater/extension_downloader.h

Index: extensions/browser/updater/extension_downloader.h
diff --git a/extensions/browser/updater/extension_downloader.h b/extensions/browser/updater/extension_downloader.h
index 81b9134ed0fa1a8c50db5013b213cb40540ab819..3de9b132bd5621b31343a42bc1478f72a0e1d58d 100644
--- a/extensions/browser/updater/extension_downloader.h
+++ b/extensions/browser/updater/extension_downloader.h
@@ -46,6 +46,7 @@ struct UpdateDetails {
 };
 
 class ExtensionCache;
+class ExtensionDownloaderTestDelegate;
 class ExtensionUpdaterTest;
 
 // A class that checks for updates of a given list of extensions, and downloads
@@ -114,6 +115,10 @@ class ExtensionDownloader : public net::URLFetcherDelegate,
     enable_extra_update_metrics_ = enable;
   }
 
+  // Sets a test delegate to use by any instances of this class. The |delegate|
+  // should outlive all instances.
+  static void set_test_delegate(ExtensionDownloaderTestDelegate* delegate);
+
   // These are needed for unit testing, to help identify the correct mock
   // URLFetcher objects.
   static const int kManifestFetcherId = 1;