Use empty name to inject JS to avoid revealing code.

If we run a named piece of JS code, v8 will try to cache it, so in the
"Source" Panel of Devtools the JS code of extension will be revealed.

Just use an empty name to run extension JS code and output the exception
messages to log.
Merge pull request #828 from PeterWangIntel/update-master-amend

Use empty name to inject JS to avoid revealing code.