MenuController Do Not SetSelection to Empty Items on Drag

ui/views/controls/menu/menu_controller.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_controller.h"
 
 #include "base/i18n/case_conversion.h"
 #include "base/i18n/rtl.h"
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 606 matching lines @@
   if (!blocking_run_)
     return false;
 
   if (possible_drag_) {
     if (View::ExceededDragThreshold(event.location() - press_pt_))
       StartDrag(source, press_pt_);
     return true;
   }
   MenuItemView* mouse_menu = NULL;
   if (part.type == MenuPart::MENU_ITEM) {
-    if (!part.menu)
-      part.menu = source->GetMenuItem();
-    else
-      mouse_menu = part.menu;
-    SetSelection(part.menu ? part.menu : state_.item, SELECTION_OPEN_SUBMENU);
+    // If there is no menu target, but a submenu target, then we are interacting
+    // with an empty menu item within a submenu. These cannot become selection
+    // targets for mouse interaction, so do not attempt to update selection.
+    if (!(!part.menu && part.submenu)) {

[sky, 2017/03/28 23:47:00]

This is rather unreadable. How about:
if (part.menu || !part.submenu) ?

[jonross, 2017/03/29 16:58:24]

Done.

+      if (!part.menu)
+        part.menu = source->GetMenuItem();
+      else
+        mouse_menu = part.menu;
+      SetSelection(part.menu ? part.menu : state_.item, SELECTION_OPEN_SUBMENU);
+    }
   } else if (part.type == MenuPart::NONE) {
     ShowSiblingMenu(source, event.location());
   }
   UpdateActiveMouseView(source, event, mouse_menu);
 
   return true;
 }
 
 void MenuController::OnMouseReleased(SubmenuView* source,
                                      const ui::MouseEvent& event) {
@@ skipping 2110 matching lines @@
   if (hot_button_)
     hot_button_->SetHotTracked(false);
   hot_button_ = hot_button;
   if (hot_button) {
     hot_button->SetHotTracked(true);
     hot_button->NotifyAccessibilityEvent(ui::AX_EVENT_SELECTION, true);
   }
 }
 
 }  // namespace views