Add bookmark entry point histogram for bookmark prompt experiment

chrome/browser/bookmarks/bookmark_utils.h

Index: chrome/browser/bookmarks/bookmark_utils.h
diff --git a/chrome/browser/bookmarks/bookmark_utils.h b/chrome/browser/bookmarks/bookmark_utils.h
index d7f0aee2d46aea5d6f0d62b3351b45ba4597f631..99bf7bd9ab856012fda252e04dc2caeea2072d6d 100644
--- a/chrome/browser/bookmarks/bookmark_utils.h
+++ b/chrome/browser/bookmarks/bookmark_utils.h
@@ -231,6 +231,17 @@ void RemoveAllBookmarks(BookmarkModel* model, const GURL& url);
 // value.
 extern int num_urls_before_prompting;
 
+// This enum is used for the Bookmarks.EntryPoint histogram.
+enum BoomarkEntryPoint {
+  ENTRY_POINT_NONE,

[sky, 2012/09/11 15:49:52]

This is never used, can it be removed?

+  ENTRY_POINT_ACCELERATOR = 0,
+  ENTRY_POINT_STAR_GESTURE,
+  ENTRY_POINT_STAR_KEY,
+  ENTRY_POINT_STAR_MOUSE,
+
+  ENTRY_POINT_LIMIT // Keep this last.
+};
+
 // This enum is used for the Bookmarks.LaunchLocation histogram.
 enum BookmarkLaunchLocation {
   LAUNCH_NONE,