Added support for multiple urls in the component updater.

BUG=304354

Review URL: https://codereview.chromium.org/101043010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241734 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241734
Created a URLListProvider that returns the user's most visited URLs, so that they can be used to predict what resources the user will fetch in the future.

BUG=306185, 309216

Review URL: https://codereview.chromium.org/105813006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241735 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241735