Add --run-before-build flag to instrumented libraries build script.

It's needed to do package-specific actions before library build.
For example, folder rename (libk5crypto3),
archive extraction (libfreetype6 and others),
makefiles patching (libbz2-1.0 and others)
We are planning to have little shell-script for each uncommon library.

BUG=313751
R=glider@chromium.org,thakis@chromium.org

Review URL: https://codereview.chromium.org/118473003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242294 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242294