[embedlite-components] Remove message listener if filepicker was canc…

…elled. Contributes to JB#53949

The FilePicker.js handle messages for filepickerresponse,
there is no cancelling if the aData is empty.
Should to remove message listener if data is empty and call returnCancell for nsIFilePicker.

jscomps/FilePicker.js

@@ -248,7 +248,14 @@ FilePicker.prototype = {
 
     this._promptActive = false;
 
-    if (!this._filePath) {
+    if (!this._filePath || !accepted) {
+      try {
+        this._callback.done(Ci.nsIFilePicker.returnCancel);
+        Services.embedlite.removeMessageListener("filepickerresponse", this);
+        delete this._callback;
+      } catch (e) {
+          Logger.warn("FilePicker: cancelling filepicker failed", e)
+      }
       return;
     }
 
@@ -265,8 +272,7 @@ FilePicker.prototype = {
       promise.then(domFile => {
                      this._domFiles.push(domFile);
                      if (this._callback && (this._domFiles.length === this._filePath.length)) {
-                       this._callback.done(this._filePath && accepted ?
-                                             Ci.nsIFilePicker.returnOK : Ci.nsIFilePicker.returnCancel);
+                       this._callback.done(Ci.nsIFilePicker.returnOK);
                        Services.embedlite.removeMessageListener("filepickerresponse", this);
                        delete this._callback;
                      }