Move messaging APIs from chrome.extension to chrome.runtime

Also leave around aliases for backwards compatability.

BUG=157952


Review URL: https://chromiumcodereview.appspot.com/11645005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@174027 0039d316-1c4b-4281-b951-d872f2087c98
17 files changed