Extensions: Send the tab id to platform apps.

chrome/renderer/resources/extensions/media_galleries_custom_bindings.js

Index: chrome/renderer/resources/extensions/media_galleries_custom_bindings.js
===================================================================
--- chrome/renderer/resources/extensions/media_galleries_custom_bindings.js	(revision 246091)
+++ chrome/renderer/resources/extensions/media_galleries_custom_bindings.js	(working copy)
@@ -5,9 +5,10 @@
 // Custom binding for the Media Gallery API.
 
 var binding = require('binding').Binding.create('mediaGalleries');
-
+var blobNatives = requireNative('blob_natives');
 var mediaGalleriesNatives = requireNative('mediaGalleries');
-var blobNatives = requireNative('blob_natives');
+var messaging = require('messaging');
+var sendRequest = require('sendRequest').sendRequest;
 
 var mediaGalleriesMetadata = {};
 
@@ -41,6 +42,13 @@
     request.callback = null;
   });
 
+  apiFunctions.setHandleRequest('addUserSelectedFolder',
+                                function() {
+    var optArgs = {customCallback: this.customCallback};
+    optArgs['senderTabId'] = mediaGalleriesNatives.GetSenderTabId();
+    sendRequest(this.name, arguments, this.definition.parameters, optArgs);
+  });
+
   // addUserSelectedFolder uses a custom callback so that it can instantiate
   // and return an array of file system objects.
   apiFunctions.setCustomCallback('addUserSelectedFolder',