Don't populate URL data in WebDropData when dragging files.

This is considered a potential security issue as well, since it leaks
filesystem paths.

BUG=332579

Review URL: https://codereview.chromium.org/135633002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244538 0039d316-1c4b-4281-b951-d872f2087c98
void TabStrip::OnDragEntered(const DropTargetEvent& event) {
  StopAnimating(true);

  UpdateDropIndex(event);

  GURL url;
   base::string16 title;
 
  if (event.data().GetURLAndTitle(
          ui::OSExchangeData::CONVERT_FILENAMES, &url, &title) &&
      url.is_valid()) {
     drop_info_->url = url;
 
    if (url.SchemeIsFile())
      controller()->CheckFileSupported(url);
  }
}

void TabStrip::OnDragEntered(const DropTargetEvent& event) {
  StopAnimating(true);

  UpdateDropIndex(event);

  GURL url;
   base::string16 title;
 
  if (event.data().GetURLAndTitle(&url, &title) && url.is_valid()) {
     drop_info_->url = url;
 
    if (url.SchemeIsFile())
      controller()->CheckFileSupported(url);
  }
}
