Add support for CefDragHandler::OnDragEnter (issue #601).

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1282 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

include/internal/cef_types.h

@@ -746,6 +746,22 @@ enum cef_errorcode_t {
   ERR_INSECURE_RESPONSE = -501,
 };
 
+///
+// "Verb" of a drag-and-drop operation as negotiated between the source and
+// destination. These constants match their equivalents in WebCore's
+// DragActions.h and should not be renumbered.
+///
+enum cef_drag_operations_mask_t {
+    DRAG_OPERATION_NONE    = 0,
+    DRAG_OPERATION_COPY    = 1,
+    DRAG_OPERATION_LINK    = 2,
+    DRAG_OPERATION_GENERIC = 4,
+    DRAG_OPERATION_PRIVATE = 8,
+    DRAG_OPERATION_MOVE    = 16,
+    DRAG_OPERATION_DELETE  = 32,
+    DRAG_OPERATION_EVERY   = UINT_MAX
+};
+
 ///
 // V8 access control values.
 ///