gtk: Do not access clipboard in renderer process.

atom/common/api/lib/clipboard.coffee

@@ -1 +1,6 @@
-module.exports = process.atomBinding 'clipboard'
+module.exports =
+  if process.platform is 'linux'
+    # On Linux we could not access clipboard in renderer process.
+    require('remote').process.atomBinding 'clipboard'
+  else
+    process.atomBinding 'clipboard'