Modify SetImageData to add additional items along with image data to save on clipboard.

extensions/browser/api/clipboard/clipboard_api.h

 // Copyright (c) 2016 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 EXTENSIONS_BROWSER_API_CLIPBOARD_CLIPBOARD_API_H_
 #define EXTENSIONS_BROWSER_API_CLIPBOARD_CLIPBOARD_API_H_
 
+#include <vector>
+
 #include "extensions/browser/browser_context_keyed_api_factory.h"
 #include "extensions/browser/extension_function.h"
 #include "extensions/common/api/clipboard.h"
 #include "ui/base/clipboard/clipboard_observer.h"
 
 namespace extensions {
 
+using AdditionalDataItemList = std::vector<api::clipboard::AdditionalDataItem>;
+
 class ClipboardAPI : public BrowserContextKeyedAPI,
                      public ui::ClipboardObserver {
  public:
   explicit ClipboardAPI(content::BrowserContext* context);
   ~ClipboardAPI() override;
 
   // BrowserContextKeyedAPI implementation.
   static BrowserContextKeyedAPIFactory<ClipboardAPI>* GetFactoryInstance();
 
   // ui::ClipboardObserver implementation.
@@ skipping 11 matching lines @@
 class ClipboardSetImageDataFunction : public UIThreadExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("clipboard.setImageData", CLIPBOARD_SETIMAGEDATA);
 
  protected:
   ~ClipboardSetImageDataFunction() override;
   ResponseAction Run() override;
 
   void OnSaveImageDataSuccess();
   void OnSaveImageDataError(const std::string& error);
+
+ private:
+  bool IsAdditionalItemsParamValid(const AdditionalDataItemList& items);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_CLIPBOARD_CLIPBOARD_API_H_