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

extensions/common/api/clipboard.idl

 // Copyright 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.
 
 // The <code>chrome.clipboard</code> API is provided to allow users to
 // access data of the clipboard. This is a temporary solution for
 // chromeos platform apps until open-web alternative is available. It will be
 // deprecated once open-web solution is available, which could be in 2017 Q2.
 [platforms=("chromeos"),
  implemented_in="extensions/browser/api/clipboard/clipboard_api.h"]
 namespace clipboard {
   // Supported image types.
   enum ImageType {png, jpeg};
   
+  enum DataItemType {text_plain, text_html};

[Devlin, 2017/05/17 16:08:44]

prefer jsCasing

[jennyz, 2017/05/18 23:33:49]

Done.

+  
+  // Additional data item to be added along with the |image_data| to describe
+  // the |image_data|.
+  dictionary AdditionalDataItem {
+    // MIME type of the additional data item, supported types are:

[Devlin, 2017/05/17 16:08:44]

"supported types" portion of this comment is out-dated.

[jennyz, 2017/05/18 23:33:49]

Done.

+    // "text/plain" and "text/html".
+    DataItemType type;
+
+    // Content of the additional data item. Either the plain text string if
+    // |type| is "text/plain" or markup string if |type| is "text/html". The
+    // data can not exceed 2MB characters.

[Devlin, 2017/05/17 16:08:44]

"2MB characters" doesn't make sense to me.  We should just say "2MB".

[jennyz, 2017/05/18 23:33:49]

Done.

+    DOMString data;
+  };
+  
   interface Events {
     // Fired when clipboard data changes.
     // Requires clipboard and clipboardRead permissions for adding listener to
     // chrome.clipboard.onClipboardDataChanged event.
     // After this event fires, the clipboard data is available by calling
     // document.execCommand('paste').
     static void onClipboardDataChanged();
   };
 
   callback SetImageDataCallback = void();
 
   interface Functions {
     // Sets image data to clipboard.
     //
     // |image_data|: The encoded image data.
     // |type|: The type of image being passed.
+    // |additional_items|: Additional data items for describing image data.
     // The callback is called with <code>chrome.runtime.lastError</code>
     // set to error code if there is an error.
     // Requires clipboard and clipboardWrite permissions.
     static void setImageData(ArrayBuffer image_data,
                              ImageType type,
+                             optional AdditionalDataItem[] additional_items,

[Devlin, 2017/05/17 16:08:44]

jsStyle

[jennyz, 2017/05/18 23:33:49]

Done.

                              SetImageDataCallback callback);
   };
 };