[NaCl SDK] Generate NOTICE file automatically.

BUG=149754
TBR=noelallen@chromium.org
R=sbc@chromium.org
NOTRY=true

Review URL: https://chromiumcodereview.appspot.com/11074004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@160711 0039d316-1c4b-4281-b951-d872f2087c98
4 files changed