Allow empty strings to be written to the clipboard

content/browser/web_contents/web_drag_dest_mac.mm

Index: content/browser/web_contents/web_drag_dest_mac.mm
diff --git a/content/browser/web_contents/web_drag_dest_mac.mm b/content/browser/web_contents/web_drag_dest_mac.mm
index a502317f7b842872f057da2a858e32d5d38160f0..7c97892dd4193da1e7f20eb77af542d1b3796f59 100644
--- a/content/browser/web_contents/web_drag_dest_mac.mm
+++ b/content/browser/web_contents/web_drag_dest_mac.mm
@@ -239,17 +239,19 @@ int GetModifierFlags() {
 
   // Get plain text.
   if ([types containsObject:NSStringPboardType]) {
-    data->plain_text =
-        base::SysNSStringToUTF16([pboard stringForType:NSStringPboardType]);
+    data->text = NullableString16(
+        base::SysNSStringToUTF16([pboard stringForType:NSStringPboardType]),
+        false);
   }
 
   // Get HTML. If there's no HTML, try RTF.
   if ([types containsObject:NSHTMLPboardType]) {
-    data->text_html =
-        base::SysNSStringToUTF16([pboard stringForType:NSHTMLPboardType]);
+    data->html = NullableString16(
+        base::SysNSStringToUTF16([pboard stringForType:NSHTMLPboardType]),
+        false);
   } else if ([types containsObject:NSRTFPboardType]) {
     NSString* html = [pboard htmlFromRtf];
-    data->text_html = base::SysNSStringToUTF16(html);
+    data->html = NullableString16(base::SysNSStringToUTF16(html), false);
   }
 
   // Get files.