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

extensions/common/api/clipboard.idl

Index: extensions/common/api/clipboard.idl
diff --git a/extensions/common/api/clipboard.idl b/extensions/common/api/clipboard.idl
index 591be7e9412054dcb8d97aa65aa65540116827d5..fc332f764f6422d455ceec5072f2dd6f0bac11e4 100644
--- a/extensions/common/api/clipboard.idl
+++ b/extensions/common/api/clipboard.idl
@@ -11,6 +11,18 @@
 namespace clipboard {
   // Supported image types.
   enum ImageType {png, jpeg};
+
+  // 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:
+    // "text/plain" and "text/html".

[Devlin, 2017/04/26 18:20:15]

if these are the only allowed types, why not an enum?

[jennyz, 2017/05/16 18:22:03]

Done.

+    DOMString 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".
+    DOMString data;

[Devlin, 2017/04/26 18:20:15]

From the implementation, I see that this has a limit, but it's not described
here in the API?

[jennyz, 2017/05/16 18:22:03]

Done.

+  };
   
   interface Events {
     // Fired when clipboard data changes.
@@ -28,11 +40,13 @@ namespace 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,
+                             AdditionalDataItem[] additional_items,

[Devlin, 2017/04/26 18:20:15]

This is not a backwards compatible change, and will break all existing clients.

[jennyz, 2017/05/16 18:22:03]

Mark the new parameter as optional.

                              SetImageDataCallback callback);
   };
 };