Split user agent code out of the 'glue' target

This creates a new user_agent component target for the user agent handling code. This makes it straightforward for iOS to build only the user-agent part of glue. It should also make incremental dismantling of webkit/ easier, since the dependencies on user agent code are now explicit.

The code that was in user_agent.cc/h (the webkit_user_agent target) has been moved to user_agent_util.cc/h, and folded into the user_agent component target. All user-agent related code has been moved to a new webkit/user_agent/ directory.

BUG=None

Review URL: https://chromiumcodereview.appspot.com/10869073

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@155695 0039d316-1c4b-4281-b951-d872f2087c98
46 files changed