Allow empty strings to be written to the clipboard

webkit/glue/webdropdata.h

Index: webkit/glue/webdropdata.h
diff --git a/webkit/glue/webdropdata.h b/webkit/glue/webdropdata.h
index 0da3e07eb4d4a08710db36638385d78342d92ace..9dd55714c3c860d1db50cbf1c1c2993ff418e2ae 100644
--- a/webkit/glue/webdropdata.h
+++ b/webkit/glue/webdropdata.h
@@ -13,6 +13,7 @@
 #include <string>
 #include <vector>
 
+#include "base/nullable_string16.h"
 #include "base/string16.h"
 #include "googleurl/src/gurl.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebReferrerPolicy.h"
@@ -61,12 +62,12 @@ struct WEBKIT_GLUE_EXPORT WebDropData {
   string16 filesystem_id;
 
   // User is dragging plain text into the webview.
-  string16 plain_text;
+  NullableString16 text;
 
   // User is dragging text/html into the webview (e.g., out of Firefox).
   // |html_base_url| is the URL that the html fragment is taken from (used to
   // resolve relative links).  It's ok for |html_base_url| to be empty.
-  string16 text_html;
+  NullableString16 html;
   GURL html_base_url;
 
   // User is dragging data from the webview (e.g., an image).