Media Galleries API: Audio/Video attached pictures support.

chrome/renderer/resources/extensions/media_galleries_custom_bindings.js

Index: chrome/renderer/resources/extensions/media_galleries_custom_bindings.js
diff --git a/chrome/renderer/resources/extensions/media_galleries_custom_bindings.js b/chrome/renderer/resources/extensions/media_galleries_custom_bindings.js
index 9b51fcc271685b3f9afbc0011f1aa4decbeb0cdd..6e2272c3a6f469b5a8a7cbaa015b526ab59140d3 100644
--- a/chrome/renderer/resources/extensions/media_galleries_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/media_galleries_custom_bindings.js
@@ -103,6 +103,22 @@ binding.registerCustomHook(function(bindingsAPI, extensionId) {
     var blobUuid = blobNatives.GetBlobUuid(mediaFile)
     return [blobUuid, options, callback];
   });
+
+  apiFunctions.setCustomCallback('getMetadata',
+                                 function(name, request, response) {
+    if (response.attachedPictures) {
+      for (var i = 0; i < response.attachedPictures.length; i++) {
+        var dataView = new DataView(response.attachedPictures[i].data);
+        var blob =
+          new Blob([dataView], {type : response.attachedPictures[i].type});
+        response.metadata.attachedPictures.push(blob);
+      }
+    }
+
+    if (request.callback)
+      request.callback(response.metadata);
+    request.callback = null;
+  });
 });
 
 exports.binding = binding.generate();