Add VIEWS_EXPORT to autoscroll constants.

views/view_constants.h

Index: views/view_constants.h
diff --git a/views/view_constants.h b/views/view_constants.h
index c00fe320f5d6d64c925a7d7027954b875501618e..cdee4bfca5d5276b6df9f35ce1db8275914c745d 100644
--- a/views/view_constants.h
+++ b/views/view_constants.h
@@ -12,11 +12,11 @@ namespace views {
 
 // Size (width or height) within which the user can hold the mouse and the
 // view should scroll.
-extern const int kAutoscrollSize;
+VIEWS_EXPORT extern const int kAutoscrollSize;
 
 // Time in milliseconds to autoscroll by a row. This is used during drag and
 // drop.
-extern const int kAutoscrollRowTimerMS;
+VIEWS_EXPORT extern const int kAutoscrollRowTimerMS;
 
 // Used to determine whether a drop is on an item or before/after it. If a drop
 // occurs kDropBetweenPixels from the top/bottom it is considered before/after