Add WebDragData to blink::WebView::dragtargetDrop

content/renderer/drop_data_builder.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/drop_data_builder.h"
 
 #include <stddef.h>
 
 #include "base/strings/string_util.h"
 #include "content/public/common/drop_data.h"
@@ skipping 19 matching lines @@
   for (size_t i = 0; i < item_list.size(); ++i) {
     const WebDragData::Item& item = item_list[i];
     switch (item.storageType) {
       case WebDragData::Item::StorageTypeString: {
         base::string16 str_type(item.stringType);
         if (base::EqualsASCII(str_type, ui::Clipboard::kMimeTypeText)) {
           result.text = base::NullableString16(item.stringData, false);
           break;
         }
         if (base::EqualsASCII(str_type, ui::Clipboard::kMimeTypeURIList)) {
-          result.url = blink::WebStringToGURL(item.stringData);
+          // The url in WebDragData received could be empty at DragEnter time,

[dcheng, 2016/06/15 12:00:39]

Let's do this this when we convert DropData::Metadata -> WebDragData so we don't
have to do an isEmpty() check here (since it's possible, though odd, for JS to
place an empty URL in the clipboard).

[hush (inactive), 2016/06/15 18:02:59]

Done.

+          // because the URL is not available at DragEnter. We need to convert
+          // to a dummy URL instead of an empty URL, because the latter means
+          // "no URL is in DropData".
+          if (item.stringData.isEmpty()) {
+            result.url = GURL("about:dragdrop-placeholder");
+          } else {
+            result.url = blink::WebStringToGURL(item.stringData);
+          }
           result.url_title = item.title;
           break;
         }
         if (base::EqualsASCII(str_type, ui::Clipboard::kMimeTypeDownloadURL)) {
           result.download_metadata = item.stringData;
           break;
         }
         if (base::EqualsASCII(str_type, ui::Clipboard::kMimeTypeHTML)) {
           result.html = base::NullableString16(item.stringData, false);
           result.html_base_url = item.baseURL;
@@ skipping 21 matching lines @@
         result.file_system_files.push_back(info);
         break;
       }
     }
   }
 
   return result;
 }
 
 }  // namespace content