[Chrome OS MD] Implement accessibility detailed view for the MD Ash system menu

ash/common/system/tray/tray_constants.h

 // 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.
 
 #ifndef ASH_COMMON_SYSTEM_TRAY_TRAY_CONSTANTS_H_
 #define ASH_COMMON_SYSTEM_TRAY_TRAY_CONSTANTS_H_
 
 #include "ash/ash_export.h"
 
 typedef unsigned int SkColor;
@@ skipping 79 matching lines @@
 // The size and foreground color of the icons appearing in the material design
 // system tray.
 extern const int kTrayIconSize;
 extern const SkColor kTrayIconColor;
 
 // The size and foreground color of the icons appearing in the material design
 // system menu.
 extern const int kMenuIconSize;
 extern const SkColor kMenuIconColor;
 
+// The margin between the menu and the icon in system menu.

[tdanderson, 2016/09/19 23:32:27]

I would suggest wording as "The margin between the edge of the menu and the edge
of the button" or similar since the spacing from the menu edge to the icon
itself would actually be 4 + 14.

[yiyix, 2016/09/21 17:10:48]

Done.

+extern const int kMenuIconMargin;
+
+// The space reserved to display menu icons in detailed view page.

[tdanderson, 2016/09/19 23:32:27]

Suggested wording: "The size of buttons in the system menu."

[yiyix, 2016/09/21 17:10:47]

Done.

+extern const int kMenuButtonSize;
+
 enum TrayConstant {
   // A legacy height value used in non-MD calculations for applying additional
   // borders on tray items.
   TRAY_ITEM_HEIGHT_LEGACY,
 
   // Padding between items in the status tray area.
   TRAY_SPACING,
 
   // Padding between the edge of shelf and the item in status tray area.
   TRAY_PADDING_FROM_EDGE_OF_SHELF,
@@ skipping 11 matching lines @@
 int GetTrayConstant(TrayConstant constant);
 
 namespace test {
 const int kSettingsTrayItemViewId = 10000;
 const int kAccessibilityTrayItemViewId = 10001;
 }  // namespace test
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_TRAY_CONSTANTS_H_