Only generate suggested filenames when actually dragging an image.

third_party/WebKit/public/platform/WebDragData.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 44 matching lines @@
       StorageTypeFilename,
       // An image being dragged out of the renderer. Contains a buffer holding
       // the image data as well as the suggested name for saving the image to.
       StorageTypeBinaryData,
       // Stores the filesystem URL of one file being dragged into the renderer.
       StorageTypeFileSystemFile,
     };
 
     StorageType storageType;
 
+    // TODO(dcheng): This should probably be a union.
     // Only valid when storageType == StorageTypeString.
     WebString stringType;
     WebString stringData;
 
+    // Title associated with a link when stringType == "text/uri-list".
+    WebString title;
+
+    // Only valid when stringType == "text/html". Stores the base URL for the
+    // contained markup.
+    WebURL baseURL;
+
     // Only valid when storageType == StorageTypeFilename.
     WebString filenameData;
     WebString displayNameData;
 
     // Only valid when storageType == StorageTypeBinaryData.
     WebData binaryData;
-
-    // Title associated with a link when stringType == "text/uri-list".
-    // Filename when storageType == StorageTypeBinaryData.
-    WebString title;
+    WebURL binaryDataSourceURL;
+    WebString binaryDataFilenameExtension;
+    WebString binaryDataContentDisposition;
 
     // Only valid when storageType == StorageTypeFileSystemFile.
     WebURL fileSystemURL;
     long long fileSystemFileSize;
     WebString fileSystemId;
-
-    // Only valid when stringType == "text/html".
-    WebURL baseURL;
   };
 
   WebDragData() : m_valid(false), m_modifierKeyState(0) {}
 
   WebDragData(const WebDragData& object)
       : m_valid(object.m_valid),
         m_itemList(object.m_itemList),
         m_modifierKeyState(object.m_modifierKeyState),
         m_filesystemId(object.m_filesystemId) {}
 
@@ skipping 37 matching lines @@
  private:
   bool m_valid;
   WebVector<Item> m_itemList;
   int m_modifierKeyState;  // State of Shift/Ctrl/Alt/Meta keys.
   WebString m_filesystemId;
 };
 
 }  // namespace blink
 
 #endif