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

ash/common/system/tray/tray_constants.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 "ash/common/system/tray/tray_constants.h"
 
 #include "ash/common/material_design/material_design_controller.h"
 #include "base/logging.h"
 #include "third_party/skia/include/core/SkColor.h"
 
@@ skipping 70 matching lines @@
 const int kTrayNotificationContentsWidth =
     kTrayPopupMinWidth - (kNotificationIconWidth + kNotificationButtonWidth +
                           (kTrayPopupPaddingHorizontal / 2) * 3);
 
 const int kMessageCenterBubblePadding = 4;
 
 const int kTrayIconSize = 16;
 const SkColor kTrayIconColor = SK_ColorWHITE;
 const int kMenuIconSize = 20;
 const SkColor kMenuIconColor = SkColorSetRGB(0x5A, 0x5A, 0x5A);
+const int kMenuIconMargin = 4;
+const int kMenuButtonSize = 48;
 
 const int kHitRegionPadding = 4;
 const SkColor kSeparatorColor = SkColorSetA(SK_ColorWHITE, 0x4D);
 const int kSeparatorWidth = 1;
 
 int GetTrayConstant(TrayConstant constant) {
   const int kTrayItemHeightLegacy[] = {38, 38, kTrayItemSize};
   const int kTraySpacing[] = {4, 4, 0};
   const int kTrayPaddingFromEdgeOfShelf[] = {3, 3, 4};
   const int kTrayPopupItemHeight[] = {46, 46, 48};
@@ skipping 13 matching lines @@
     case TRAY_POPUP_ITEM_HEIGHT:
       return kTrayPopupItemHeight[mode];
     case VIRTUAL_KEYBOARD_BUTTON_SIZE:
       return kVirtualKeyboardButtonSize[mode];
   }
   NOTREACHED();
   return 0;
 }
 
 }  // namespace ash