Add UMA for window.external.AddSearchProvider (Chrome side).

chrome/browser/ui/search_engines/edit_search_engine_controller.h

Index: chrome/browser/ui/search_engines/edit_search_engine_controller.h
diff --git a/chrome/browser/ui/search_engines/edit_search_engine_controller.h b/chrome/browser/ui/search_engines/edit_search_engine_controller.h
index b1d988d74a41a0f057c5a31c44544db67a1fabb7..92fc3d58c58df97dd04132bce03207a27c479f78 100644
--- a/chrome/browser/ui/search_engines/edit_search_engine_controller.h
+++ b/chrome/browser/ui/search_engines/edit_search_engine_controller.h
@@ -33,6 +33,16 @@ class EditSearchEngineControllerDelegate {
 // for the Edit Search Engine dialog.
 class EditSearchEngineController {
  public:
+  // An enum to match the AddSearchProvider UMA enum. Values should not be
+  // changed; new ones must be added at the bottom.
+  enum EditSearchEngineActions {
+    ADD_SEARCH_PROVIDER_CALLED = 0,
+    CONFIRMATION_DIALOG_SHOWN = 1,
+    CONFIRMATION_DIALOG_CONFIRMED = 2,
+    CONFIRMATION_DIALOG_CANCELLED = 3,
+    NUM_EDIT_SEARCH_ENGINE_ACTIONS
+  };
+
   // The |template_url| and/or |edit_keyword_delegate| may be NULL.
   EditSearchEngineController(
       TemplateURL* template_url,