Add bookmark entry point histogram for bookmark prompt experiment

chrome/browser/bookmarks/bookmark_utils.cc

Index: chrome/browser/bookmarks/bookmark_utils.cc
diff --git a/chrome/browser/bookmarks/bookmark_utils.cc b/chrome/browser/bookmarks/bookmark_utils.cc
index 22aa178928b820713d5d5c7b687b5c123ee77380..477b336225cde6e41d5ea4b9e289eec075278935 100644
--- a/chrome/browser/bookmarks/bookmark_utils.cc
+++ b/chrome/browser/bookmarks/bookmark_utils.cc
@@ -25,6 +25,7 @@
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/simple_message_box.h"
 #include "chrome/common/pref_names.h"
+#include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
@@ -697,6 +698,7 @@ void AddIfNotBookmarked(BookmarkModel* model,
   if (!bookmarks.empty())
     return;  // Nothing to do, a bookmark with that url already exists.
 
+  content::RecordAction(content::UserMetricsAction("BookmarkAdded"));
   const BookmarkNode* parent = model->GetParentForNewNodes();
   model->AddURL(parent, parent->child_count(), title, url);
 }