Only generate suggested filenames when actually dragging an image.

third_party/WebKit/Source/core/clipboard/DataObjectItem.h

 /*
  * Copyright (C) 2011 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 38 matching lines @@
                                           const String& data);
   static DataObjectItem* createFromFile(File*);
   // File with non-empty filesystem ID can be converted into FileEntry by using
   // webkitGetAsEntry.
   static DataObjectItem* createFromFileWithFileSystemId(
       File*,
       const String& fileSystemId);
   static DataObjectItem* createFromURL(const String& url, const String& title);
   static DataObjectItem* createFromHTML(const String& html,
                                         const KURL& baseURL);
-  static DataObjectItem* createFromSharedBuffer(const String& filename,
-                                                PassRefPtr<SharedBuffer>);
+  static DataObjectItem* createFromSharedBuffer(
+      PassRefPtr<SharedBuffer>,
+      const KURL&,
+      const String& fileExtension,
+      const AtomicString& contentDisposition);
   static DataObjectItem* createFromPasteboard(const String& type,
                                               uint64_t sequenceNumber);
 
   ItemKind kind() const { return m_kind; }
   String type() const { return m_type; }
   String getAsString() const;
   File* getAsFile() const;
 
   // Used to support legacy DataTransfer APIs and renderer->browser
   // serialization.
   PassRefPtr<SharedBuffer> sharedBuffer() const { return m_sharedBuffer; }
+  String filenameExtension() const { return m_filenameExtension; }
   String title() const { return m_title; }
   KURL baseURL() const { return m_baseURL; }
   bool isFilename() const;
 
   bool hasFileSystemId() const;
   String fileSystemId() const;
 
   DECLARE_TRACE();
 
  private:
   enum DataSource {
     PasteboardSource,
     InternalSource,
   };
 
   DataObjectItem(ItemKind, const String& type);
   DataObjectItem(ItemKind, const String& type, uint64_t sequenceNumber);
 
   DataSource m_source;
   ItemKind m_kind;
   String m_type;
 
   String m_data;
   Member<File> m_file;
   RefPtr<SharedBuffer> m_sharedBuffer;
   // Optional metadata. Currently used for URL, HTML, and dragging files in.
+  String m_filenameExtension;
   String m_title;
   KURL m_baseURL;
 
   uint64_t m_sequenceNumber;  // Only valid when m_source == PasteboardSource
   String m_fileSystemId;      // Only valid when m_file is backed by FileEntry.
 };
 
 }  // namespace blink
 
 #endif  // DataObjectItem_h