Add bookmark entry point histogram for bookmark prompt experiment

chrome/browser/ui/views/frame/browser_view.cc

Index: chrome/browser/ui/views/frame/browser_view.cc
diff --git a/chrome/browser/ui/views/frame/browser_view.cc b/chrome/browser/ui/views/frame/browser_view.cc
index 7fb2ea9701ee6b0c4c180dc2654e25bf85b52ec8..5736d010ff8684245b2c3fc5cb867f536cfa6210 100644
--- a/chrome/browser/ui/views/frame/browser_view.cc
+++ b/chrome/browser/ui/views/frame/browser_view.cc
@@ -2399,6 +2399,10 @@ void BrowserView::UpdateAcceleratorMetrics(
   if (command_id == IDC_HELP_PAGE_VIA_KEYBOARD && key_code == ui::VKEY_F1)
     content::RecordAction(UserMetricsAction("ShowHelpTabViaF1"));
 
+  if (command_id == IDC_BOOKMARK_PAGE)
+    UMA_HISTOGRAM_ENUMERATION("Bookmarks.EntryPoint", location,
+                              BOOKMARK_ENTRY_POINT_ACCELERATOR);
+
 #if defined(OS_CHROMEOS)
   // Collect information about the relative popularity of various accelerators
   // on Chrome OS.