See also this announcement:

We have removed the option '--disallow-unsafe-eval' from dart2js.

Who is affected?

Developers of Chrome extensions or developers who serve JavaScript code with a header Content-Security-Policy: script-src 'self'. This policy disallows using 'eval' and 'new Function' in JavaScript code.

How do I update my code?

Remove the option '--disallow-unsafe-eval' from your build scripts. The compiler will always generate two JavaScript output files:
out.js
out.precompiled.js
The second file is for CSP mode.

Why did this change happen?

This change was made to simplify the user experience (one less option), and to simplify the implementation of CSP mode in dart2js. This allowed us to support 'dart:mirrors' in CSP mode which wasn't supported before.

We have monitored test cycle times and benchmarks, and generating this additional file doesn't seem to have any measurable effect.

When will the change take effect?

This change is already landed in bleeding_edge, and should make it to the next stable build.

Where can I learn more?

If you're interested in learning more about CSP, see: http://developer.chrome.com/extensions/contentSecurityPolicy.html

If you want to learn how to parse a "CSP policy policy", see http://www.w3.org/TR/2012/CR-CSP-20121115/#parsing

Set owner to @kwalrath.
Added this to the 1.1 milestone.
Added Duplicate label.
Marked as being merged into #9987.