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

extensions/browser/api/clipboard/clipboard_api.h

Index: extensions/browser/api/clipboard/clipboard_api.h
diff --git a/extensions/browser/api/clipboard/clipboard_api.h b/extensions/browser/api/clipboard/clipboard_api.h
index 00be111d57453fe3e868f8e426d471bd97d4c702..00578ca40f470b201b262f38d3624eff3a636a5e 100644
--- a/extensions/browser/api/clipboard/clipboard_api.h
+++ b/extensions/browser/api/clipboard/clipboard_api.h
@@ -12,6 +12,8 @@
 
 namespace extensions {
 
+using AdditionalDataItemList = std::vector<api::clipboard::AdditionalDataItem>;
+
 class ClipboardAPI : public BrowserContextKeyedAPI,
                      public ui::ClipboardObserver {
  public:
@@ -43,6 +45,9 @@ class ClipboardSetImageDataFunction : public UIThreadExtensionFunction {
 
   void OnSaveImageDataSuccess();
   void OnSaveImageDataError(const std::string& error);
+
+ private:
+  bool IsAdditionalItemsParamValid(const AdditionalDataItemList& items);
 };
 
 }  // namespace extensions