Experimental drag&drop in DocumentsUI

Change-Id: If8911f33c6e1de2252d5bdcd5862799c5c4a202a
diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index 06f65e2..195c83c 100644
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -39,4 +39,6 @@
 
     <dimen name="dir_elevation">8dp</dimen>
 
+    <dimen name="drag_shadow_size">120dp</dimen>
+
 </resources>