Minor adjustment to edge padding of 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 6035312a3da9ead13c35aaedddc53187c2d72ac3..691c0f5b69f722518e1252390a9314132931b62e 100644
--- a/ash/common/system/tray/tray_constants.h
+++ b/ash/common/system/tray/tray_constants.h
@@ -96,6 +96,10 @@ extern const int kHorizontalSeparatorHeight;
 extern const int kTrayIconSize;
 extern const SkColor kTrayIconColor;
 
+// The total visual padding at the start and end of the icon/label section
+// of the tray.
+extern const int kTrayEdgePadding;
+
 // The size and foreground color of the icons appearing in the material design
 // system menu.
 extern const int kMenuIconSize;