Make UMA_HISTOGRAM_ENUMERATION work with scoped enums.

ash/common/shelf/shelf_view.h

Index: ash/common/shelf/shelf_view.h
diff --git a/ash/common/shelf/shelf_view.h b/ash/common/shelf/shelf_view.h
index 860dbe8e87c4423e207fbc8f4229cbf5ac75d977..139f42c29f71c3ffc330df780fed42813b166180 100644
--- a/ash/common/shelf/shelf_view.h
+++ b/ash/common/shelf/shelf_view.h
@@ -54,10 +54,12 @@ namespace test {
 class ShelfViewTestAPI;
 }
 
-extern const int SHELF_ALIGNMENT_UMA_ENUM_VALUE_BOTTOM;
-extern const int SHELF_ALIGNMENT_UMA_ENUM_VALUE_LEFT;
-extern const int SHELF_ALIGNMENT_UMA_ENUM_VALUE_RIGHT;
-extern const int SHELF_ALIGNMENT_UMA_ENUM_VALUE_COUNT;
+enum ShelfAlignmentUmaEnumValue {
+  SHELF_ALIGNMENT_UMA_ENUM_VALUE_BOTTOM,
+  SHELF_ALIGNMENT_UMA_ENUM_VALUE_LEFT,
+  SHELF_ALIGNMENT_UMA_ENUM_VALUE_RIGHT,
+  SHELF_ALIGNMENT_UMA_ENUM_VALUE_COUNT,

[rkaplow, 2017/03/29 18:02:50]

Seems a bit easy to miss that this last needs to be last, can you add a space
and something like // Must be last entry in enum.

[dcheng, 2017/03/29 18:24:40]

Done.

+};
 
 class ASH_EXPORT ShelfView : public views::View,
                              public ShelfModelObserver,