Activate comboboxes (i.e. open dropdown menu) on Enter and Space.

ui/views/controls/combobox/combobox.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/combobox/combobox.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 583 matching lines @@
     case ui::VKEY_HOME:
     case ui::VKEY_PRIOR:  // Page up.
       new_index = GetAdjacentIndex(model(), 1, -1);
       break;
 
     // Move to the previous item if any.
     case ui::VKEY_UP:
       new_index = GetAdjacentIndex(model(), -1, selected_index_);
       break;
 
-    // Click the button only when the button style mode.
     case ui::VKEY_SPACE:
       if (style_ == STYLE_ACTION) {
         // When pressing space, the click event will be raised after the key is
         // released.
         text_button_->SetState(Button::STATE_PRESSED);
       } else {
-        return false;
+        show_menu = true;
       }
       break;
 
-    // Click the button only when the button style mode.
     case ui::VKEY_RETURN:
-      if (style_ != STYLE_ACTION)
-        return false;
-      OnPerformAction();
+      if (style_ == STYLE_ACTION)
+        OnPerformAction();
+      else
+        show_menu = true;
       break;
 
     default:
       return false;
   }
 
   if (show_menu) {
     ShowDropDownMenu(ui::MENU_SOURCE_KEYBOARD);
   } else if (new_index != selected_index_ && new_index != kNoSelection &&
              style_ != STYLE_ACTION) {
@@ skipping 281 matching lines @@
 }
 
 int Combobox::GetArrowContainerWidth() const {
   int padding = style_ == STYLE_NORMAL
                     ? PlatformStyle::kComboboxNormalArrowPadding * 2
                     : kActionLeftPadding + kActionRightPadding;
   return ArrowSize().width() + padding;
 }
 
 }  // namespace views