Added finch experiment to track new menu style effect.

ui/views/controls/menu/menu_runner.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/menu/menu_runner.h"
 
 #include <set>
 
+#include "base/metrics/histogram.h"
 #include "ui/views/controls/button/menu_button.h"
 #include "ui/views/controls/menu/menu_controller.h"
 #include "ui/views/controls/menu/menu_controller_delegate.h"
 #include "ui/views/controls/menu/menu_delegate.h"
+#include "ui/views/controls/menu/submenu_view.h"
 #include "ui/views/widget/widget.h"
 
 #if defined(OS_WIN)
 #include "base/win/win_util.h"
 #endif
 
 namespace views {
 
 namespace internal {
 
+void RecordSelectedIndexes(const MenuItemView* menu_item) {
+  if (!menu_item)
+    return;
+  const MenuItemView* parent = menu_item->GetParentMenuItem();
+  if (!parent)
+    return;
+
+  SubmenuView* submenu = parent->GetSubmenu();
+  for (int i = 0; i < submenu->GetMenuItemCount(); ++i) {
+    if (submenu->GetMenuItemAt(i) == menu_item) {
+      HISTOGRAM_COUNTS_100("MenuSelection.Index", i);
+      break;
+    }
+  }
+
+  RecordSelectedIndexes(parent);

[sky, 2013/03/07 21:05:00]

Don't we only care about the index of the actual item?

[yefimt, 2013/03/07 22:17:52]

For multi-level menus I think we need to report index for each level.
If root menu has a submenu with index 10 and selected item from that submenu has
index 1, then reporting only 1 will loose information that user was able to
select submenu with index 10 on a top level.

On 2013/03/07 21:05:00, sky wrote:

+}
+
+void RecordMenuStats(MenuItemView* result, base::TimeDelta time_elapsed) {
+  // Report if user made a selection.
+  HISTOGRAM_BOOLEAN("MenuSelection", result != NULL);
+
+  if (result) {
+    // Report how much time it took to make a selection.
+    HISTOGRAM_TIMES("MenuSelection.Time", time_elapsed);
+    RecordSelectedIndexes(result);
+  }
+}
+
 // Manages the menu. To destroy a MenuRunnerImpl invoke Release(). Release()
 // deletes immediately if the menu isn't showing. If the menu is showing
 // Release() cancels the menu and when the nested RunMenuAt() call returns
 // deletes itself and the menu.
 class MenuRunnerImpl : public internal::MenuControllerDelegate {
  public:
   explicit MenuRunnerImpl(MenuItemView* menu);
 
   MenuItemView* menu() { return menu_; }
 
@@ skipping 118 matching lines @@
         // We can't open another menu, otherwise the message loop would become
         // twice nested. This isn't necessarily a problem, but generally isn't
         // expected.
         return MenuRunner::NORMAL_EXIT;
       }
       // Drop menus don't block the message loop, so it's ok to create a new
       // MenuController.
       controller = NULL;
     }
   }
+
   running_ = true;
   for_drop_ = (types & MenuRunner::FOR_DROP) != 0;
   bool has_mnemonics = (types & MenuRunner::HAS_MNEMONICS) != 0 && !for_drop_;
   owns_controller_ = false;
   if (!controller) {
     // No menus are showing, show one.
     ui::NativeTheme* theme = parent ? parent->GetNativeTheme() :
         ui::NativeTheme::instance();
     controller = new MenuController(theme, !for_drop_, this);
     owns_controller_ = true;
   }
   controller_ = controller;
   menu_->set_controller(controller_);
   menu_->PrepareForRun(owns_controller_,
                        has_mnemonics,
                        !for_drop_ && ShouldShowMnemonics(button));
 
   // Run the loop.
+  base::TimeTicks start_time = base::TimeTicks::Now();
   int mouse_event_flags = 0;
   MenuItemView* result = controller->Run(parent, button, menu_, bounds, anchor,
                                         (types & MenuRunner::CONTEXT_MENU) != 0,
                                          &mouse_event_flags);
 
   if (for_drop_) {
     // Drop menus return immediately. We finish processing in DropMenuClosed.
     return MenuRunner::NORMAL_EXIT;
   }
-
+  RecordMenuStats(result, base::TimeTicks::Now() - start_time);
   return MenuDone(result, mouse_event_flags);
 }
 
 void MenuRunnerImpl::Cancel() {
   if (running_)
     controller_->Cancel(MenuController::EXIT_ALL);
 }
 
 void MenuRunnerImpl::DropMenuClosed(NotifyType type, MenuItemView* menu) {
   MenuDone(NULL, 0);
@@ skipping 101 matching lines @@
 
 bool MenuRunner::IsRunning() const {
   return holder_->running();
 }
 
 void MenuRunner::Cancel() {
   holder_->Cancel();
 }
 
 }  // namespace views