Register clipboard image blob in the browser process to copy data less.

content/renderer/webclipboard_impl.h

 // Copyright (c) 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.
 
 #ifndef CONTENT_RENDERER_WEBCLIPBOARD_IMPL_H_
 #define CONTENT_RENDERER_WEBCLIPBOARD_IMPL_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 15 matching lines @@
   uint64_t sequenceNumber(Buffer buffer) override;
   bool isFormatAvailable(Format format, Buffer buffer) override;
   blink::WebVector<blink::WebString> readAvailableTypes(
       Buffer buffer,
       bool* contains_filenames) override;
   blink::WebString readPlainText(Buffer buffer) override;
   blink::WebString readHTML(Buffer buffer,
                             blink::WebURL* source_url,
                             unsigned* fragment_start,
                             unsigned* fragment_end) override;
-  blink::WebData readImage(Buffer buffer) override;
+  blink::WebBlobInfo readImage(Buffer buffer) override;
   blink::WebString readCustomData(Buffer buffer,
                                   const blink::WebString& type) override;
   void writePlainText(const blink::WebString& plain_text) override;
   void writeHTML(const blink::WebString& html_text,
                  const blink::WebURL& source_url,
                  const blink::WebString& plain_text,
                  bool write_smart_paste) override;
   void writeImage(const blink::WebImage& image,
                   const blink::WebURL& source_url,
                   const blink::WebString& title) override;
   void writeDataObject(const blink::WebDragData& data) override;
 
  private:
   bool ConvertBufferType(Buffer, ui::ClipboardType*);
   RendererClipboardDelegate* const delegate_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_WEBCLIPBOARD_IMPL_H_