Adding the cr command base class

BUG=316397

Review URL: https://codereview.chromium.org/72043002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235741 0039d316-1c4b-4281-b951-d872f2087c98
Adding the info command.

BUG=316397

Review URL: https://codereview.chromium.org/72723003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235742 0039d316-1c4b-4281-b951-d872f2087c98
Adding the concept of a target platform.

BUG=316397

Review URL: https://codereview.chromium.org/72733002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235743 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235742
SVN changes up to revision 235743