[Chrome OS MD] Update spacing between material design icons in the system tray

ash/common/system/tray/tray_constants.h

Index: ash/common/system/tray/tray_constants.h
diff --git a/ash/common/system/tray/tray_constants.h b/ash/common/system/tray/tray_constants.h
index 0ed8c6319dbce99ef1726bbe4a15162a41454693..1501c787df4ea17cb4a610ccc6cef2784e8ea22b 100644
--- a/ash/common/system/tray/tray_constants.h
+++ b/ash/common/system/tray/tray_constants.h
@@ -24,9 +24,7 @@ extern const int kBubblePaddingVerticalSide;
 
 extern const int kTrayBubbleAnchorTopInsetBottomAnchor;
 
-extern const int kTrayImageItemHorizontalPaddingBottomAlignment;
 extern const int kTrayImageItemHorizontalPaddingVerticalAlignment;
-extern const int kTrayImageItemVerticalPaddingVerticalAlignment;
 
 ASH_EXPORT extern const int kTrayItemSize;
 
@@ -119,6 +117,9 @@ enum TrayConstant {
 
   // The icon size of opt-in IME menu tray.
   TRAY_IME_MENU_ICON,
+
+  // The padding needed between 2 items in the tray area in the shelf.

[tdanderson, 2016/10/05 21:34:29]

The spec says we need a padding of 6 between two items. It looks like you're
using this to specify the padding on one side of a single icon (which would give
a total between-icon padding of 3+3=6). That's fine, but can you reword the
comment to something like "extra padding beside a single icon" instead of
"padding between two items"?

also, nit: 2 -> "two"

[yiyix, 2016/10/05 22:46:47]

Done.

+  TRAY_IMAGE_ITEM_PADDING,
 };
 
 int GetTrayConstant(TrayConstant constant);