Modify WebView drop effect override values.

webkit/glue/webview_impl.h

Index: webkit/glue/webview_impl.h
diff --git a/webkit/glue/webview_impl.h b/webkit/glue/webview_impl.h
index 0b8db724415dee02d32c4cfe6d95856ae096321f..15915b0d4deff8dbfb8933f0fd524b8abeebff17 100644
--- a/webkit/glue/webview_impl.h
+++ b/webkit/glue/webview_impl.h
@@ -331,11 +331,11 @@ class WebViewImpl : public WebView, public base::RefCounted<WebViewImpl> {
   int32 drag_identity_;
 
   // Valid when drag_target_dispatch_ is true.  Used to override the default
-  // browser drop effect with the effects "copy" or "none".
+  // browser drop effect with the effects "none" or "copy".
   enum DragTargetDropEffect {
-    DROP_EFFECT_DEFAULT = 0,
-    DROP_EFFECT_COPY,
-    DROP_EFFECT_NONE
+    DROP_EFFECT_DEFAULT = -1,
+    DROP_EFFECT_NONE,
+    DROP_EFFECT_COPY
   } drop_effect_;
 
   // When true, the drag data can be dropped onto the current drop target in