Revert "[test] convert manual test case "tray" to automatic"

This reverts commit 522aec266ddbf8b3f9bfdc26d5a648db5a89bd73.
Grant file: scheme to the renderer processes

Fix #871
Add App.getProxyForURL() to query proxy for URL

Fix #130
add test case for load remote img(need to put index.html under imgshown to server doc root)