Explicitly: This reverts the patch that reverted the patch that
removed the majority of absolute paths from linux builds, and makes
it possible to use an absolute path by setting dont_embed_build_metadata
to false.

In conjunction with codereview.chromium.org/1642193002 that modifies the codesearch
buildbot to use dont_embed_build_metadata = false, this CL should allow
codesearch to continue working, and all other buildbots and users
to gain the benefits of not requiring absolute paths.

BUG=580103

Review URL: https://codereview.chromium.org/1643523004

Cr-Commit-Position: refs/heads/master@{#373432}