Build is pulling stuff in from //chrome

[Chris Coulson]

It has been noticed that some builds contain all Chrome strings in the shipped resource files. Looking at the build logs, I see warnings like this:

ninja: warning: multiple rules generate gen/repack/ar.pak. builds involving this target will not be correct; continuing anyway

Something is depending on chrome.gyp:packed_resources, causing duplicate targets and making the builds non-reproducible. The resource files that end up in the finished build depend on whatever way the wind is blowing.