Revert of Add output reference to gen written files. (patchset #3 id:40001 of https...

Revert of Add output reference to gen written files. (patchset #3 id:40001 of https://codereview.chromium.org/1220223002/)

Reason for revert:
Looks like this doesn't quite work on Windows:

http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_ng/builds/21206/steps/compile%20%28with%20patch%29/logs/stdio

Original issue's description:
> Add output reference to gen written files.
>
> By adding the outputs written at gn gen time to the build.ninja representation the build tool (ninja) can know how to recreate them if and when necessary.
>
> For example, if one or more of the <blah>.tmp files is removed, even as part of an entire hierarchy/subtree currently the build fails because ninja does not know how to re-make it.
>
> BUG=469621
> TEST=Build time only. See https://code.google.com/p/chromium/issues/detail?id=469621#c3
>
> Committed: https://crrev.com/517ac52f86903beb206b19e6ddeedbc709b253a1
> Cr-Commit-Position: refs/heads/master@{#338929}

TBR=brettw@chromium.org,petermayo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=469621

Review URL: https://codereview.chromium.org/1255113004

Cr-Commit-Position: refs/heads/master@{#340596}