Removes files from //build that we don't need

build/linux/unbundle/README

-This directory contains files that make it possible to use system libraries.
-
-For more info please read the following:
-
- - https://fedoraproject.org/wiki/Packaging:No_Bundled_Libraries
- - https://wiki.gentoo.org/wiki/Why_not_bundle_dependencies
- - http://www.debian.org/doc/debian-policy/ch-source.html#s-embeddedfiles
-
-For more Chromium-specific context please read
-http://spot.livejournal.com/312320.html .
-
-This directory is provided in the source tree to follow above guidelines.
-It is a compromise solution which takes into account Chromium developers
-who want to avoid the perceived burden of more conditional code in gyp,
-and expectations of Open Source community, where using system-provided
-libraries is the norm.
-
-Usage:
-
-1. remove_bundled_libraries.py <preserved-directories>
-
-   For example: remove_bundled_libraries.py third_party/mesa
-
-   The script scans sources looking for third_party directories.
-   Everything that is not explicitly preserved is removed (except for
-   gyp files), and the script fails if any directory passed on command
-   line does not exist (to ensure list is kept up to date).
-
-   This is intended to be used on sources extracted from a tarball,
-   not a repository.
-
-   NOTE: by default this will not remove anything (for safety). Pass
-   --do-remove flag to actually remove files.
-
-2. replace_gyp_files.py <gyp-flags>
-
-   For example: replace_gyp_files.py -Duse_system_harfbuzz=1
-
-   The script ignores flags other than -D for convenience. This makes it
-   possible to have a variable e.g. ${myconf} with all the options, and
-   execute:
-
-   build/linux/unbundle/replace_gyp_files.py ${myconf}
-   build/gyp_chromium ${myconf}