Implementation of beginning of Declarative Web Request API backend

This CL implements the beginning of the RulesRegistry for the Declarative Web Request API; it allows registering rules and checking whether their conditions are fulfilled.

BUG=112155
TEST=no

Review URL: https://chromiumcodereview.appspot.com/9820003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@129585 0039d316-1c4b-4281-b951-d872f2087c98