Use vector icon for Ash shelf launcher

ash/common/shelf/shelf_constants.h

Index: ash/common/shelf/shelf_constants.h
diff --git a/ash/common/shelf/shelf_constants.h b/ash/common/shelf/shelf_constants.h
index a4fd87e4d43a0d05f58f7469a4c6697a4cc3e5d2..e2f12e3b09cc2f17b185423a2fc0232ead537f77 100644
--- a/ash/common/shelf/shelf_constants.h
+++ b/ash/common/shelf/shelf_constants.h
@@ -6,6 +6,7 @@
 #define ASH_COMMON_SHELF_SHELF_CONSTANTS_H_
 
 #include "ash/ash_export.h"
+#include "third_party/skia/include/core/SkColor.h"
 
 namespace ash {
 
@@ -29,6 +30,9 @@ ASH_EXPORT extern const int kShelfButtonSize;
 // Animation duration for switching black shelf and dock background on and off.
 ASH_EXPORT extern const int kTimeToSwitchBackgroundMs;
 
+// The color of the icons used in the shelf (launcher, notifications, etc).

[James Cook, 2016/06/07 15:51:52]

nit: foreground color? background color?

[tdanderson, 2016/06/08 17:29:27]

Done.

+ASH_EXPORT extern const SkColor kShelfIconColor;
+
 // The direction of the focus cycling.
 enum CycleDirection { CYCLE_FORWARD, CYCLE_BACKWARD };